Question

2.) what does the --ate ending in nitrate tell us? (1 point)
there are 3 oxygen atoms
there are 4 oxygen atoms
it is a polyatomic ion
that it has 1- charge

Explanation:

1. Analyze each option:

• Option 1: The number of oxygen atoms in nitrate ($\ce{NO_3^-}$) is 3, but the “-ate” ending doesn't directly indicate the number of oxygen atoms (e.g., sulfate $\ce{SO_4^{2-}}$ has 4, carbonate $\ce{CO_3^{2-}}$ has 3). So this is not the main meaning of “-ate”.
• Option 2: Nitrate has 3 oxygen atoms, not 4, so this is incorrect.
• Option 3: The “-ate” suffix in polyatomic ions (like nitrate, sulfate, carbonate) indicates that it is a polyatomic ion (a charged species composed of two or more atoms covalently bonded). This is a key use of the “-ate” ending in naming polyatomic ions.
• Option 4: The charge of nitrate is 1-, but the “-ate” ending doesn't directly tell the charge (e.g., sulfate has 2- charge). So this is not the meaning of “-ate”.

Answer:

C. It is a polyatomic ion