Molecules containing two carbon atoms and a functional group have many home and industrial uses. these compounds can be produced by a variety of reactions, as shown by

Group of atoms that react to the compounds in a predictable or a desired way is called a functional group. Few of the examples for these varied reactions which produce these compounds are  
1: C2H4 + H2O → CH3CH2OH 
 2: 2CH3CH2OH + O2 → 2CH3CHO + 2H2O
 3: 2CH3CHO + O2 → 2CH3COOH

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

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

1. o2(g)as a product