Question

write the chemical formula for the compound formed by each pair of positive and negative ions.
ba²⁺ and no₃⁻:
al³⁺ and co₃²⁻:
k⁺ and po₄³⁻:

Explanation:

Step1: Balance charges for Ba²⁺ and NO₃⁻

To balance the +2 charge of Ba²⁺, we need 2 NO₃⁻ ions.

Step2: Write the chemical formula

The formula is Ba(NO₃)₂.

Step3: Balance charges for Al³⁺ and CO₃²⁻

To balance the +3 charge of Al³⁺ and - 2 charge of CO₃²⁻, we use the least - common multiple of 2 and 3. We need 2 Al³⁺ ions and 3 CO₃²⁻ ions.

Step4: Write the chemical formula

The formula is Al₂(CO₃)₃.

Step5: Balance charges for K⁺ and PO₄³⁻

To balance the +1 charge of K⁺ and - 3 charge of PO₄³⁻, we need 3 K⁺ ions.

Step6: Write the chemical formula

The formula is K₃PO₄.

Answer:

Ba(NO₃)₂
Al₂(CO₃)₃
K₃PO₄