A certain metal hydroxide, m (oh) 2, contains 32.8% oxygen by mass. what is the identity of the metal m?

Total mass = x

It would be: x*32.38/100 = 32

x = 3200/32.38 = 97.56

Atomic mass of (OH) 2 = 34

So, remaining mass = 97.56-34 = 63.56

which is approximately equal to mass of copper

So, we can say m is copper here, and formula of the compound would be Cu (OH) 2