Summary
The Periodic Table arranges elements by increasing atomic number, placing elements with similar properties in the same column, known as groups. Group 1 elements, also called alkali metals, are highly reactive metals with one electron in their outer shell.
- Periodic Table — a table that organizes elements by increasing atomic number. Example: Elements in the same group have similar properties.
- Group 1 Elements — metals in the first column of the periodic table, known as alkali metals. Example: Lithium, sodium, and potassium are group 1 elements.
- Period — horizontal rows in the periodic table indicating the number of electron shells. Example: Elements in period 2 have two electron shells.
- Group — vertical columns in the periodic table showing the number of outer electrons. Example: Group 4 elements have four electrons in their outer shell.
Exam Tips
Key Definitions to Remember
- Periodic Table: Arrangement of elements by increasing atomic number.
- Group 1 Elements: Alkali metals with one electron in their outer shell.
- Period: Horizontal rows in the periodic table.
- Group: Vertical columns in the periodic table.
Common Confusions
- Confusing periods with groups.
- Misunderstanding why reactivity increases down Group 1.
Typical Exam Questions
- What is the periodic table? A table arranging elements by increasing atomic number.
- Why are Group 1 elements highly reactive? They have one electron in their outer shell, which is easily lost.
- How does reactivity change in Group 1 elements? Reactivity increases as you go down the group.
What Examiners Usually Test
- Understanding of periodic trends and group properties.
- Ability to explain why Group 1 elements are reactive.
- Knowledge of how the periodic table is organized.