Atoms, Elements and Compounds

Worked examples (3)

• 1Classifying dissolving salt as a physical change
• 2Evidence that iron rusting is a chemical change
• 3Identifying physical vs chemical changes from a list

Worked examples (3)

• 1Classifying substances
• 2Differences between compound and mixture
• 3Why water is a compound, not a mixture of hydrogen and oxygen

Worked examples (4)

• 1Sub-atomic particles in phosphorus
• 2Electronic configuration of chlorine
• 3Isotopes of carbon
• 4Calculating relative atomic mass

Worked examples (4)

• 1Dot-and-cross diagram of sodium chloride
• 2Why ionic compounds have high melting points
• 3Electrical conductivity — solid vs molten NaCl
• 4MgO vs NaCl melting points

Worked examples (4)

• 1Dot-and-cross diagram of water
• 2Why methane has a low boiling point
• 3Diamond vs graphite electrical conductivity
• 4Triple bond in nitrogen

Worked examples (4)

• 1Why silicon dioxide has a very high melting point
• 2Why metals are malleable
• 3Thermosoftening vs thermosetting polymers
• 4Metallic bonding and electrical conductivity