Carbon can make four bonds. Since it is doubly bonded carbon, it means it can make two more bonds. So, two more hydrogen atoms could help in bond formation.

Two H atoms are attached to each carbon.
Answer:
Ionic bonding occurs between atoms that have opposite needs for electrons (metals and nonmetals) and results in a transfer of electrons. Covalent bonding occurs between atoms that have similar needs for electrons (two nonmetals) and results in a sharing of electrons.
Explanation:
Answer:
Lose two electrons.
Explanation:
Barium is present in group 2.
It is alkaline earth metal.
Its atomic number is 56.
Its electronic configuration is Ba₅₆ = [Xe] 6s².
In order to attain the noble gas electronic configuration it must loses its two valance electrons.
When barium loses it two electron its electronic configuration will equal to the Xenon.
The atomic number of xenon is 54 so barium must loses two electrons to becomes equal to the xenon.