Question

sebastian wants to write the chemical formula for phosphorus tetraoxide. he identifies the chemical symbols as p and o. which additional step will he take in his process? identify the elements involved as potassium and oxygen add a subscript of 4 after the o write the chemical symbols, in order, as op use the prefix tetra before oxygen

Explanation:

• In chemical formula writing for covalent compounds like phosphorus tetraoxide:
• The prefixes indicate the number of atoms. "Tetra - " means 4.
• For the formula, the first element (phosphorus, \(P\)) is written first, then the second element (oxygen, \(O\)) with the prefix - derived subscript.
• Option 1: \(P\) is phosphorus, not potassium (\(K\)), so this is wrong.
• Option 2: Since "tetra - " refers to oxygen atoms, adding a subscript of 4 after \(O\) (formula \(P_2O_4\) - the 2 for phosphorus comes from valence considerations in a more complex sense, but the key here is the subscript for \(O\) based on prefix) is correct.
• Option 3: The formula order is first element (phosphorus) then second (oxygen), so \(OP\) is wrong.
• Option 4: The prefix is already used in naming (\("tetraoxide"\)), in the formula we use subscript, not repeat the prefix.

Answer:

add a subscript of 4 after the \(O\)