question 15 of 20\nwhat is the chemical formula for the compound formed between potassium and…

Explanation:

Step1: Determine potassium ion

Potassium (K) is in Group 1 of the periodic - table and forms a $K^+$ ion by losing one electron.

Step2: Determine iodine ion

Iodine (I) is in Group 17 and forms an $I^-$ ion by gaining one electron.

Step3: Write formula for K - I compound

To form a neutral compound, the ratio of $K^+$ to $I^-$ is 1:1, so the formula is KI.

Step4: Determine oxygen ion

Oxygen (O) is in Group 16 and forms an $O^{2 - }$ ion by gaining two electrons.

Step5: Write formula for K - O compound

To balance the charges, we need two $K^+$ ions for one $O^{2 - }$ ion. The formula is $K_2O$.

Answer:

Formula for potassium - iodine compound: KI Formula for potassium - oxygen compound: $K_2O$