Chemical Names, Formulas & Polyatomic Ions — Drills · Grade 11 Science
Chapter: Bonding, Formulas & Molecular StructureWhat these drills covers
By the end of Chemical Names, Formulas & Polyatomic Ions you should be able to:
- I can write neutral ionic formulas with polyatomic ions.
- I can distinguish molecular prefixes, subscripts, and metal-charge numerals.
2 questions, written answer and numeric, each with a worked explanation.
Vocabulary used: polyatomic ion, Roman numeral, subscript.
Problem 1
Write the formula of magnesium nitrate.
Answer and explanation
Mg(NO₃)₂: one Mg²⁺ balances two NO₃⁻.
Response criteria
- State a scientifically accurate conclusion.
- Show the calculation or mechanism that supports it.
- Include units, conditions, or limits where relevant.
Problem 2
Count oxygen atoms in 2Al₂(SO₄)₃.
Hints
Write the relationship first; substitute with consistent units.
Answer and explanation
24 atoms
2 ×3 ×4 = 24.