For which of the following compounds must we specify the charge on the metal when we name the compound: Cr(NO3)2, Ba(NO3)2, AlBr3, NiS, ZnCl2?

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

b.

the accuracy of the data.

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;