Question

A scientist is investigating the structure of aluminum nitrate, which has the chemical formula Al(NO3)3. Based on the chemical formula, what can the scientist predict about the structure of this molecule?
It has three NO3 groups.

It has three aluminum (Al) atoms.

It has one NO3 group.

It has nine nitrogen (N) atoms.

Answer 1

The chemical formula of aluminium nitrate is - Al(NO₃)₃
cation is Al³⁺
anion is NO₃⁻
One Al atom binds to three nitrate groups 
the options given are 
2. It has three aluminum (Al) atoms 
this is incorrect as there's only one Al atom 
3. It has one NO3 group.
this is incorrect as there are three nitrate groups
4. It has nine nitrogen (N) atoms
there are only 3 N atoms therefore this too is incorrect 
therefore the correct answer is - 
It has three NO₃ groups