Construct the formulas of the connection by vollence. S (6) O, N (3) H, KS (2), DIN (3), C (4) O

1: S (6) O, in order to formulate a compound by valency, you must first determine the least common multiple of these two chemical elements;

Since we know that S has (6), and O always has valency (2), the smallest common multiple is 6, therefore we get the formula SO3 (higher sulfur oxide);

2: N (3) H, hydrogen always has a valency of 1, so the smallest common multiple will be 3, therefore we get NH3 (ammonia);

3: KS (2), potassium has a valency of 1, then we get K2S (potassium sulfide);

4: DIN (3), no such chemical compound exists;

5: C (4) O, since oxygen has a valency of 2, we get CO₂ (carbon dioxide);