Understanding Polyatomic Ions and Chemical Formulas

What page in the SRC Yr 10 Chemistry and Physics Data booklet can you find the polyatomic ions?

• You can't they have to be memorised

• Page 6

• Page 8

• Page 3

What defines a polyatomic ion?

• A group of atoms that forms a charged entity

• A single atom with a charge

• A molecule without a charge

• A group of atoms with a neutral charge

How do you balance the charge of Calcium Nitrate?

• By removing one Nitrate ion

• By adding two Nitrate ions

• By adding another Calcium atom

• By changing the charge of Calcium

How many Ammonium ions are needed to balance the charge with one Nitride ion?

• Two

• One

• Three

• Four

What is the charge of Ammonium?

• +1

• 0

• -1

• +2

Why is it unnecessary to use parentheses for a single polyatomic ion in a formula?

• Only if the ion has a negative charge

• If you're not multiplying it by a number

• Only if the ion has a positive charge

• It's always required

What is the correct formula for Magnesium Phosphate with balanced charges?

• Mg2PO4

• Mg3(PO4)2

• Mg(PO4)3

• MgPO4

Can the charge of a polyatomic ion be determined without memorization?

• Yes, by calculating the valence electrons

• No, memorization is required

• Yes, using a formula

• Sometimes, depending on the ion