What is #"CaC"_1#?
CaC₁ is not a correct formula for any compound.
Carbon is in Group 14, so it has four valence electrons.
If a carbon atom added four electrons to get an octet, it would form the ion C⁴⁻. The ionic compound with Ca²⁺ would have the formula Ca₂C.
But we know that carbon forms covalent bonds, not ionic bonds.
The compound acetylene (ethyne, HC≡CH) forms the acetylide ion (⁻C≡C⁻). With Ca²⁺ it forms the ionic compound calcium carbide, CaC₂.
Hope this helps.