No such substance as 'NaCl2'. However, NaCl (sodium chloride or common table salt) has two atoms viz. 1 x sodium(Na) and 1 x chlorine(Cl).
The common name for NaCl2 is sodium hypochlorite.
the atoms share electrons
Atoms in a compound are held together by chemical bonds, which are formed when atoms share or transfer electrons to achieve a stable configuration. These bonds can be covalent, where atoms share electrons, or ionic, where electrons are transferred between atoms.
minimum two atoms are for single covalent bond
This question seems a bit unclear. Perhaps it meant something like: "how many electrons can be shared with carbon atoms?" Anyway, a carbon atom can share 4 electrons with other atoms, including other carbon atoms.
I know that table salt has no hydrogen atoms; NaCl2
The common name for NaCl2 is sodium hypochlorite.
NaCl2 does not exist. Perhaps you are referring to NaCl, in which case the cation is Na^+.
electrons share ionic bond between atoms. Covalent bond may also be present.
Covalent bonds are formed when atoms share electrons
a carbon atom can share electrons with up to four other atoms.
Atoms share electrons when they form covalent bonds.
A covalent bond forms when atoms share electrons.
hydrogen atoms share electrons when it forms covalent bonds
"NaCl2" in Tamil refers to "நேசியம் குருமி" which translates to "sodium chloride". It is commonly known as table salt in English.
covalent bond (There is also metallic bonding, which is many, many atoms sharing an electron, not just neighboring electrons.)
two electrons