the oxidation number of Mo in Na2MoO4 is what?

Answer 1

Compounds must add up to zero.
Na is +1; 2*1 = +2
O is -2; 4*-2 = -8
So Mo must be ...... for Na2MoO4 to be zero.

Answer 2

Na2MoO4= 0×2+x+4(-2)=0
=0+x+(-6)=0
= x-6=0
𝘼𝙣𝙨𝙬𝙚𝙧 =x=6
𝙒𝙝𝙚𝙣 𝙬𝙚 𝙛𝙞𝙣𝙙 𝙤𝙭𝙞𝙙𝙖𝙩𝙞𝙤𝙣 𝙨𝙩𝙖𝙩𝙚 𝙤𝙛 𝙈𝙤