Why is "Saying the periodic table is arranged 'by atomic mass'" a common mistake in Understanding the periodic table?

Why it happens: Students remember Mendeleev's historical table (which used mass) and apply it to the modern table. How to avoid it: The MODERN table is ordered by **atomic (proton) number**. Reserve 'mass' for Mendeleev only — write 'atomic number' in the answer. Source: Edexcel Chemistry examiner reports — recurring error

Why is "Swapping group and period (using the row for outer electrons, or the column for shells)" a common mistake in Understanding the periodic table?

Why it happens: The two terms are easy to confuse under time pressure. How to avoid it: Lock in: **GROUP (column) = outer electrons**; **PERIOD (row) = number of shells**. Source: Edexcel Chemistry examiner reports

Why is "Writing electron configurations that don't total the atomic number (e.g. magnesium as 2, 8, 8, 2)" a common mistake in Understanding the periodic table?

Why it happens: Students add an extra shell or fill the second shell with too many electrons. How to avoid it: Fill shells in the order **2, then 8, then 8**, and check the digits add up to the **atomic number** (magnesium = 12 → 2, 8, 2). Source: Edexcel Chemistry examiner reports

Why is "Giving the correct size of ion charge but the wrong sign (e.g. oxygen as +2 instead of −2)" a common mistake in Understanding the periodic table?

Why it happens: Students count the electrons gained/lost but forget that gaining negative electrons gives a negative ion. How to avoid it: Metals **lose** electrons → **positive**; non-metals **gain** electrons → **negative**. Decide metal/non-metal first, then the sign follows. Source: Edexcel Chemistry examiner reports

Why is "Giving Group 0 (noble gases) an ion charge" a common mistake in Understanding the periodic table?

Why it happens: Students apply the 'group number → charge' rule mechanically without thinking. How to avoid it: Group 0 elements already have a **full outer shell**, so they do **not** form ions. State 'no ion' / 'does not form ions'. Source: Edexcel Chemistry examiner reports

Why is "Explaining similar group properties as 'they are in the same group' without mentioning electrons" a common mistake in Understanding the periodic table?

Why it happens: Students state the position but not the underlying reason the mark scheme wants. How to avoid it: Always give the cause: elements in a group have the **same number of outer-shell electrons**, which control chemical behaviour. Source: Edexcel Chemistry examiner reports

The Periodic TableEdexcel IGCSE Science(Double Award)-Chemistry (4WSD0-1C)

Understanding the periodic table

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Understanding the Periodic Table — Edexcel International GCSE Science (Double Award) Chemistry (4WSD0-1C) Study Notes

How the modern periodic table is built — elements in order of increasing atomic (proton) number, arranged into Groups (vertical, same outer-shell electrons → similar properties) and Periods (horizontal, same number of shells). How to use an element's POSITION to predict its electron arrangement, ion charge and whether it is a metal or non-metal. Covers Double Award Chemistry spec 1.84–1.87, assessed on Chemistry Paper 1 (4WSD0/1C).

What you’ll learn

Mapped to the Edexcel IGCSE 4WSD0-1C syllabus (2026 onwards).

1.84 — Understand that the periodic table is arranged in order of increasing atomic (proton) number.
1.85 — Recall that elements in the same group have similar chemical properties because they have the same number of outer-shell electrons.
1.86 — Recall the positions of metals and non-metals in the periodic table.
1.87 — Use the position of an element to predict its electron configuration and likely properties.

Arranged by increasing atomic (proton) number (spec 1.84)

Every element is placed in order of its atomic (proton) number — one more proton each step.

The modern periodic table lists every known element in order of increasing atomic (proton) number — the number of protons in the nucleus.

Reading left → right along a row, the atomic number goes up by 1 each time: each element has one more proton than the one before it.
Because a neutral atom has equal protons and electrons, each element also has one more electron than the element before it.
Hydrogen (atomic number 1) comes first; helium (2) next; lithium (3), and so on.

Watch out: the table is NOT arranged by atomic mass. The historic version built by Mendeleev used atomic mass, but the modern table uses atomic (proton) number. This is a favourite one-mark trap — always say "atomic number" or "proton number", never "mass".

The atomic (proton) number rises by one with each element across the table.

Order by atomic (proton) number, NOT atomic mass.
Each element has one more proton than the one before.
A neutral atom has equal protons and electrons.
Say 'atomic number' / 'proton number' in answers — never 'mass'.

See the full worked example for understanding the periodic table →

Groups and periods — what the position tells you (spec 1.85)

Groups = columns (same outer electrons → similar properties); periods = rows (same number of shells).

The table is a grid, and where an element sits tells you about its electron arrangement.

Vertical columns = GROUPS.

All elements in the same group have the SAME NUMBER OF OUTER-SHELL ELECTRONS.
Outer-shell electrons control how an element reacts, so elements in the same group have SIMILAR CHEMICAL PROPERTIES.
For Groups 1, 2, 3, 4, 5, 6 and 7: group number = number of outer-shell electrons.
For Group 0 (the noble gases): the outer shell is FULL (2 for helium; 8 for the rest).

Group	Outer electrons	Family name	Typical ion
1	1	Alkali metals	+1
2	2	Alkaline earth metals	+2
6	6	(oxygen group)	−2
7	7	Halogens	−1
0	8 (full)	Noble gases	none

Horizontal rows = PERIODS.

The period number = the number of occupied electron shells.
Going across a period, each element gains one more proton AND one more electron, but the same number of shells — the outer shell simply fills up across the row.

Period	Number of shells	Outer shell filling
1	1	H, He
2	2	Li → Ne
3	3	Na → Ar

Groups are columns (same outer electrons), periods are rows (same number of shells).

The big idea: because group members share the number of outer electrons, knowing one element in a group lets you predict the behaviour of the others. That is why the table is so useful.

Group = column → same number of outer-shell electrons → similar properties.
Group number = number of outer electrons (1–7); Group 0 = full outer shell.
Period = row → period number = number of occupied electron shells.
Across a period the outer shell fills; the number of shells stays the same.

See the full worked example for understanding the periodic table →

Where the metals and non-metals are (spec 1.86)

Metals fill the left and centre; non-metals sit to the right of the staircase line.

The periodic table is split into metals and non-metals by a stepped, zig-zag line often called the 'staircase'.

Metals occupy the LEFT and CENTRE of the table — this is most of the elements (Groups 1, 2, the central transition metals, and the lower-left of the p-block).
Non-metals are crowded into the TOP-RIGHT, above and to the right of the staircase line (most of Groups 4–7 plus the Group 0 noble gases).
Hydrogen is usually drawn above Group 1 but behaves like a non-metal — treat it as a special case.

Quick properties to remember.

	Metals	Non-metals
Position	left + centre	right (above staircase)
Conduct electricity?	yes	usually no (graphite is the exception)
State at room temp	mostly solid	many gases; some solid; Br₂ liquid
When they form ions	LOSE electrons → positive ions	GAIN electrons → negative ions
Oxides	basic (e.g. Na₂O)	acidic (e.g. SO₂, CO₂)

Why metals lose and non-metals gain electrons. Metals have few outer electrons (1, 2 or 3) — it is easier to lose those than to gain a full shell. Non-metals have many outer electrons (5, 6 or 7) — it is easier to gain a few than to lose lots. Both end up with a stable, full outer shell.

Metals: left and centre of the table (the majority of elements).
Non-metals: top-right, above/right of the staircase line.
Metals lose electrons → positive ions; non-metals gain electrons → negative ions.
Hydrogen sits above Group 1 but behaves like a non-metal.

See the full worked example for understanding the periodic table →

Using position to predict configuration, ion charge & properties (spec 1.87)

Period → number of shells; group → outer electrons → ion charge → metal or non-metal.

This is the skill examiners reward most: take an element's position and read off its chemistry. Follow four steps.

Step 1 — period gives the number of shells. The period (row) number = the number of occupied electron shells.

Step 2 — group gives the outer electrons. The group number = the number of electrons in the outer shell (Group 0 = full outer shell).

Step 3 — build the electron configuration. Fill shells 2, 8, 8 in order until you have used all the electrons (the total = the atomic number). The last number is the outer-shell count from Step 2.

Step 4 — predict the ion charge & type.

Metals (Groups 1–3) LOSE their outer electrons → ions of charge +1, +2, +3.
Non-metals (Groups 5–7) GAIN electrons to fill the shell → ions of charge −3, −2, −1.
Group 0 forms no ions (full shell already).

Group	Outer e⁻	Electrons lost/gained	Ion charge
1	1	lose 1	+1
2	2	lose 2	+2
3	3	lose 3	+3
5	5	gain 3	−3
6	6	gain 2	−2
7	7	gain 1	−1
0	8 (full)	none	no ion

Worked logic — sodium (Na). Sodium is in Period 3, Group 1 with atomic number 11.

Period 3 → 3 shells.
Group 1 → 1 outer electron → configuration 2, 8, 1.
1 outer electron, a metal on the left → loses 1 electron → forms Na⁺.
It is a metal: conducts electricity, forms a basic oxide, reactive (alkali metal).

Period 3, Group 1 → three shells, one outer electron → forms a +1 ion.

Do the same for any element: period = shells, group = outer electrons, then decide lose or gain.

Period number = number of shells; group number = outer electrons.
Build configuration by filling 2, 8, 8 up to the atomic number.
Metals (Gp 1–3) lose → +1/+2/+3; non-metals (Gp 5–7) gain → −3/−2/−1.
Group 0 has a full outer shell → forms no ions.

See the full worked example for understanding the periodic table →

How it’s examined

Double Award Chemistry is assessed on one untiered paper — Chemistry Paper 1 (4WSD0/1C), 2 hours, 110 marks, 33.3% of the Double Award (calculator allowed). 'Understanding the periodic table' is a guaranteed source of marks: state how the table is arranged (atomic number); say why elements in a group are similar (same number of outer-shell electrons); locate metals vs non-metals; and — the highest-value skill — use an element's position to give its electron configuration and predicted ion charge. The most common dropped mark is writing 'arranged by mass' instead of 'atomic (proton) number'.

Sources: Pearson Edexcel International GCSE Science (Double Award) 4SD0 specification — Issue 4 (valid for 2026 onwards); Pearson Edexcel International GCSE Chemistry 4CH1 specification — Issue 4 (shared Chemistry Paper 1 content); Pearson Edexcel 4SD0 / 4CH1 examiner reports 2022–2024. Last reviewed 2026-06-07.

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Step-by-step worked examples — Understanding the periodic table

Step-by-step solutions to past-paper-style questions on understanding the periodic table, written exactly the way a tutor would explain them at the board.

1What the table is arranged by (Getting started)
Getting started• 4WSD0/1C style — short answer• arrangement, spec-1.84
Question
State the property used to order the elements in the modern periodic table. (1 mark)
Step-by-step solution
1. Step 1
  Recall the rule (1). The modern table is arranged in order of increasing atomic (proton) number.
2. Step 2
  Avoid the trap. It is NOT arranged by atomic mass — that was Mendeleev's old approach. 'Mass' scores zero here.
Answer
Increasing atomic (proton) number.
Examiner tip
A single, easy mark that students throw away by writing 'atomic mass' or 'atomic weight'. The required word is 'number' (proton number is also accepted).
2Read group and period from a position (Getting started)
Getting started• 4WSD0/1C style — short answer• groups, periods, spec-1.85
Question
An element is in Group 6 and Period 3. State (a) its number of outer-shell electrons and (b) its number of occupied electron shells. (2 marks)
Step-by-step solution
1. Step 1
  (a) Group → outer electrons (1). Group number = number of outer-shell electrons, so Group 6 → 6 outer electrons.
2. Step 2
  (b) Period → shells (1). Period number = number of occupied electron shells, so Period 3 → 3 shells.
Answer
(a) 6 outer-shell electrons; (b) 3 occupied shells.
Examiner tip
Two independent marks. Students who muddle group and period lose both. Memorise: GROUP = outer electrons, PERIOD = shells.
3Decide metal or non-metal from position (Building confidence)
Building confidence• 4WSD0/1C style — structured• metals, non-metals, spec-1.86
Question
Element X is in Group 2 and element Y is in Group 7. State whether each is a metal or a non-metal, and give the charge of the ion each forms. (4 marks)
Step-by-step solution
1. Step 1
  X type (1). Group 2 is on the left of the table → X is a metal.
2. Step 2
  X ion (1). A Group 2 metal has 2 outer electrons and loses 2 → ion charge +2 (X²⁺).
3. Step 3
  Y type (1). Group 7 is on the right of the staircase → Y is a non-metal.
4. Step 4
  Y ion (1). A Group 7 non-metal has 7 outer electrons and gains 1 → ion charge −1 (Y⁻).
Answer
X is a metal forming a +2 ion (X²⁺); Y is a non-metal forming a −1 ion (Y⁻).
Examiner tip
Position fixes everything: left = metal that loses electrons (positive ion); right = non-metal that gains electrons (negative ion). Always state the sign as well as the number.
4Full electron configuration from position (Building confidence)
Building confidence• 4WSD0/1C style — structured• electron-configuration, spec-1.87
Question
Magnesium has atomic number 12 and sits in Group 2, Period 3. Give its electron configuration and the charge of the ion it forms, explaining how you used its position. (4 marks)
Step-by-step solution
1. Step 1
  Shells from period (1). Period 3 → 3 occupied shells.
2. Step 2
  Outer electrons from group (1). Group 2 → 2 electrons in the outer shell.
3. Step 3
  Build it (1). Fill 2, then 8, then the remainder: 2 + 8 + 2 = 12 electrons → configuration 2, 8, 2.
4. Step 4
  Ion charge (1). A Group 2 metal loses its 2 outer electrons → forms Mg²⁺.
Answer
Configuration 2, 8, 2; magnesium loses 2 electrons to form Mg²⁺.
Examiner tip
The total of the configuration must equal the atomic number (2 + 8 + 2 = 12). A common slip is writing 2, 8, 8, 2 — check shells fill in the order 2, 8, 8.
5Explain why a group behaves alike (Stretch)
Stretch• 4WSD0/1C style — extended• groups, spec-1.85, reasoning
Question
Lithium, sodium and potassium are all in Group 1 and all react with water in a similar way. Explain, in terms of electron arrangement, why these three elements have similar chemical properties. (3 marks)
Step-by-step solution
1. Step 1
  Same group, same outer electrons (1). Being in the same group, all three have the same number of outer-shell electrons — one each.
2. Step 2
  Outer electrons control reactions (1). It is the outer-shell electrons that take part in chemical reactions and so determine an element's chemical properties.
3. Step 3
  Link (1). Because Li, Na and K each react by losing their single outer electron, they react in the same way → similar chemical properties.
Answer
They are in the same group, so they have the same number of outer-shell electrons (one each). The outer electrons control chemical behaviour, and all three react by losing that single outer electron, so they show similar chemical properties.
Examiner tip
The mark-scheme phrase is 'same number of outer-shell electrons'. Vague answers like 'they are in the same group so they're similar' without mentioning outer electrons miss the explanation mark.
6Predict properties of an unfamiliar element (Stretch)
Stretch• 4WSD0/1C style — extended• prediction, spec-1.87, application
Question
Rubidium (Rb) is the element directly below potassium in Group 1. Using its position, predict (a) the number of outer-shell electrons, (b) the charge of the ion it forms, (c) whether it is a metal or non-metal, and (d) one way it would react with water compared with potassium. (4 marks)
Step-by-step solution
1. Step 1
  (a) Outer electrons (1). Group 1 → 1 outer-shell electron.
2. Step 2
  (b) Ion charge (1). A Group 1 metal loses its 1 outer electron → +1 ion (Rb⁺).
3. Step 3
  (c) Metal or non-metal (1). Group 1 is on the far left → rubidium is a metal.
4. Step 4
  (d) Reactivity (1). Reactivity increases down Group 1, so rubidium reacts more vigorously with water than potassium (an explosive reaction).
Answer
(a) 1 outer electron; (b) +1 (Rb⁺); (c) metal; (d) reacts more vigorously/violently with water than potassium.
Examiner tip
This is the whole point of the periodic table — position lets you predict an element you have never met. For part (d), accept any clear statement that it is more reactive than the element above it.

Model Answers — Understanding the periodic table

High-scoring sample answers for understanding the periodic table on the Pearson Edexcel IGCSE Chemistry Paper 1 (4WSD0/1C) paper, with examiner-style notes mapping each response to the mark scheme and assessment objectives.

Question 1
4WSD0/1C style3 marks
State how the elements are ordered in the modern periodic table, and name the two terms used for the vertical columns and the horizontal rows. (3 marks)
Model answer
The elements are arranged in order of increasing atomic (proton) number. (1)

The vertical columns are called groups. (1)

The horizontal rows are called periods. (1)
Why this scores
1 mark each. Do not write 'arranged by mass' — that loses the first mark. Columns = groups, rows = periods (a frequently swapped pair).
Question 2
4WSD0/1C style4 marks
For an element in Group 1, Period 2 of the periodic table, state: (a) its number of outer-shell electrons; (b) its number of occupied electron shells; (c) whether it is a metal or a non-metal; (d) the charge of the ion it forms. (4 marks)
Model answer
(a) Group 1 → 1 outer-shell electron. (1)

(b) Period 2 → 2 occupied shells. (1)

(c) Group 1 is on the left → it is a metal. (1)

(d) It loses its 1 outer electron → forms a +1 ion. (1)
Why this scores
GROUP gives outer electrons and ion type; PERIOD gives shells. The element here is lithium (2, 1) — but you can answer entirely from its position without naming it.
Question 3
4WSD0/1C style4 marks
Fluorine and chlorine are both in Group 7. Explain why they have similar chemical properties. (4 marks)
Model answer
Fluorine and chlorine are in the same group of the periodic table. (1)

Elements in the same group have the same number of outer-shell electrons — here, 7 outer electrons each. (1)

It is the outer-shell electrons that take part in chemical reactions, so they control an element's chemical properties. (1)

Both elements react by gaining 1 electron (to fill the outer shell), so they behave in the same way and have similar chemical properties. (1)
Why this scores
The discriminating mark is 'same number of outer-shell electrons'. Stating that outer electrons control reactivity AND that both gain one electron lifts the answer into the top band.
Question 4
4WSD0/1C style4 marks
Describe where metals and non-metals are found in the periodic table, and explain why metals form positive ions while non-metals form negative ions. (4 marks)
Model answer
Metals are found on the left and centre of the periodic table. (1)

Non-metals are found on the right, above/to the right of the staircase (zig-zag) line. (1)

Metals have few outer electrons (1, 2 or 3), which they lose to gain a stable full outer shell — losing negative electrons leaves a positive ion. (1)

Non-metals have many outer electrons (5, 6 or 7), which they fill by gaining electrons — adding negative electrons makes a negative ion. (1)
Why this scores
Mention the staircase line for the non-metal position mark. The ion-charge marks require linking 'lose electrons → positive' and 'gain electrons → negative', not just stating the charges.
Question 5
4WSD0/1C style — extended6 marks
Sulfur has atomic number 16 and is found in Group 6, Period 3 of the periodic table. Using its position, deduce its electron configuration, state and explain the charge of the ion it forms, and predict whether it conducts electricity. (6 marks)
Model answer
Electron configuration.

Period 3 → 3 occupied shells; Group 6 → 6 outer electrons. (1)

Filling 2, 8, then the remainder: 2 + 8 + 6 = 16 → configuration 2, 8, 6. (1)

Ion charge.

Sulfur is a non-metal on the right of the table with 6 outer electrons. (1)

It gains 2 electrons to complete its outer shell to 8, forming a −2 ion (S²⁻). (1) Gaining negative electrons gives a negative ion. (1)

Conductivity.

As a non-metal, sulfur does not conduct electricity. (1)
Why this scores
The configuration total must equal the atomic number (2 + 8 + 6 = 16). The ion mark needs the direction of electron transfer (gains 2) plus the correct sign and size (−2). Stating 'non-metal → does not conduct' secures the final mark.
Question 6
4WSD0/1C style — extended8 marks
Element A is in Group 2, Period 4; element B is in Group 7, Period 2. For each element, deduce its number of outer-shell electrons, the charge of the ion it forms, and whether it is a metal or non-metal. Then state the formula of the compound formed when A and B react together. (8 marks)
Model answer
Element A (Group 2, Period 4).

2 outer-shell electrons (Group 2). (1)

Loses 2 electrons → +2 ion (A²⁺). (1)

On the left of the table → metal. (1)

Element B (Group 7, Period 2).

7 outer-shell electrons (Group 7). (1)

Gains 1 electron → −1 ion (B⁻). (1)

On the right of the table → non-metal. (1)

Compound formula.

A²⁺ needs to balance with B⁻ ions; the +2 charge requires two −1 ions. (1)

Formula = AB₂. (1)
Why this scores
The final two marks test ionic-formula balancing using charges read from position: a +2 ion combines with two −1 ions to give AB₂. This is exactly how examiners stretch a position-prediction question to the top of the paper.

Key Definitions and Keywords — Understanding the periodic table

Definitions to memorise and the exact keywords mark schemes credit for understanding the periodic table answers — sharpened from recent examiner reports for the 2026 Pearson Edexcel IGCSE Chemistry Paper 1 (4WSD0/1C) sitting.

Periodic table
Examiner keyword
A table of all the chemical elements arranged in order of increasing atomic (proton) number, in groups (columns) and periods (rows).
Atomic (proton) number
Examiner keyword
The number of protons in the nucleus of an atom; the property used to order elements in the modern periodic table.
Group
Examiner keyword
A vertical column of the periodic table. Elements in the same group have the same number of outer-shell electrons and therefore similar chemical properties.
Period
Examiner keyword
A horizontal row of the periodic table. The period number equals the number of occupied electron shells in atoms of those elements.
Outer-shell electrons
Examiner keyword
The electrons in the highest occupied energy level of an atom; they take part in chemical reactions and determine chemical properties. Group number = number of outer-shell electrons.
Metal
Examiner keyword
An element found on the left and centre of the periodic table that conducts electricity and tends to lose its outer electrons to form positive ions.
Non-metal
Examiner keyword
An element found on the right of the periodic table (above the staircase line) that usually does not conduct electricity and tends to gain electrons to form negative ions.
Staircase line
The stepped, zig-zag line in the periodic table that separates the metals (to the left) from the non-metals (to the right).
Electron configuration
The arrangement of an atom's electrons in shells, written from the inside out (e.g. sodium = 2, 8, 1). Shells fill in the order 2, 8, 8.
Ion charge (from position)
The charge on the ion an element forms: metals in Groups 1–3 lose electrons to give +1, +2 or +3; non-metals in Groups 5–7 gain electrons to give −3, −2 or −1; Group 0 forms no ions.

Common Mistakes and Misconceptions — Understanding the periodic table

The traps other students keep falling into on understanding the periodic table questions — taken from recent Pearson Edexcel IGCSE Chemistry Paper 1 (4WSD0/1C) examiner reports and mark schemes — and how to avoid them.

✕Saying the periodic table is arranged 'by atomic mass'
Edexcel Chemistry examiner reports — recurring error
Why it happens
Students remember Mendeleev's historical table (which used mass) and apply it to the modern table.
How to avoid it
The MODERN table is ordered by atomic (proton) number. Reserve 'mass' for Mendeleev only — write 'atomic number' in the answer.
✕Swapping group and period (using the row for outer electrons, or the column for shells)
Edexcel Chemistry examiner reports
Why it happens
The two terms are easy to confuse under time pressure.
How to avoid it
Lock in: GROUP (column) = outer electrons; PERIOD (row) = number of shells.
✕Writing electron configurations that don't total the atomic number (e.g. magnesium as 2, 8, 8, 2)
Edexcel Chemistry examiner reports
Why it happens
Students add an extra shell or fill the second shell with too many electrons.
How to avoid it
Fill shells in the order 2, then 8, then 8, and check the digits add up to the atomic number (magnesium = 12 → 2, 8, 2).
✕Giving the correct size of ion charge but the wrong sign (e.g. oxygen as +2 instead of −2)
Edexcel Chemistry examiner reports
Why it happens
Students count the electrons gained/lost but forget that gaining negative electrons gives a negative ion.
How to avoid it
Metals lose electrons → positive; non-metals gain electrons → negative. Decide metal/non-metal first, then the sign follows.
✕Giving Group 0 (noble gases) an ion charge
Edexcel Chemistry examiner reports
Why it happens
Students apply the 'group number → charge' rule mechanically without thinking.
How to avoid it
Group 0 elements already have a full outer shell, so they do not form ions. State 'no ion' / 'does not form ions'.
✕Explaining similar group properties as 'they are in the same group' without mentioning electrons
Edexcel Chemistry examiner reports
Why it happens
Students state the position but not the underlying reason the mark scheme wants.
How to avoid it
Always give the cause: elements in a group have the same number of outer-shell electrons, which control chemical behaviour.

Past paper style quiz

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Understanding the periodic table

Detailed Notes

What you’ll learn

How it’s examined

1What the table is arranged by (Getting started)

2Read group and period from a position (Getting started)

3Decide metal or non-metal from position (Building confidence)

4Full electron configuration from position (Building confidence)

5Explain why a group behaves alike (Stretch)

6Predict properties of an unfamiliar element (Stretch)

Periodic table

Atomic (proton) number

Group

Period

Outer-shell electrons

Metal

Non-metal

Staircase line

Electron configuration

Ion charge (from position)

✕Saying the periodic table is arranged 'by atomic mass'

✕Swapping group and period (using the row for outer electrons, or the column for shells)

✕Writing electron configurations that don't total the atomic number (e.g. magnesium as 2, 8, 8, 2)

✕Giving the correct size of ion charge but the wrong sign (e.g. oxygen as +2 instead of −2)

✕Giving Group 0 (noble gases) an ion charge

✕Explaining similar group properties as 'they are in the same group' without mentioning electrons

Past paper style quiz