Chemical bonds: ionic and covalent
Answers are for parents and teachers.
1
A lithium atom (2, 1) becomes Li⁺. Write the arrangement of Li⁺ and say which noble gas it copies.
2: the same as helium.
2
Explain how LiF forms and why it is neutral.
Lithium gives one electron to fluorine, making Li⁺ and F⁻. The charges +1 and −1 cancel.
3
Draw the picture of a chlorine molecule Cl₂ with its bond.
Cl–Cl: one shared pair, a single bond.
4
Write two differences between typical ionic and covalent compounds.
Ionic: high melting point, conduct electricity when dissolved. Covalent: often a low melting point, poor conductors.
5
Draw a methane molecule (CH₄) and count the bonds on the carbon atom.
Carbon is joined to four hydrogen atoms by four single bonds.