How many in Q.(4) are neutral ?

How many in Q.(4) are basic ?

How many compounds are neutral ? H_(2)O , NaOH , HCL ,Nacl

Out of the following oxides of nitrogen how many of them are neutral oxides? N_(2)O, NO, N_(2)O_(3), NO_(2),N_(2)O_(4), N_(2)O_(5)

How many -4's are there in -20?

How many secounds are there in 4 days?

How many elements are there in 4^(th) period? Prove it.

How many orbitals are thre in 4f shell ?