There are 2 carbon (C) atoms and 2 hydrogen (H) atoms in a C2H2 molecule. Each carbon (C) atom in acetylene has 4 valence electrons and tends to form 4 covalent bonds to satisfy its octet rule. Each hydrogen (H) atom in acetylene has 1 valence electron and tends to form 1 covalent bond.

To determine the number of covalent bonds in the C2H2 molecule, we can add the valence electrons of all atoms and divide the total by 2.

Total valence electrons in C2H2 = (2 × 4 valence electrons of C) + (2 × 1 valence electron of H) = 10

Number of covalent bonds in C2H2 = (Total valence electrons) / 2 = 10 / 2 = 5

Therefore, the C2H2 molecule has 5 covalent bonds.