Formation of Compound between Atom X and Atom Y:
The compound formed between atom X and atom Y can be determined by considering their valence electrons. Atom X has seven valence electrons, while atom Y has two valence electrons. To achieve a stable electron configuration, atom X needs to gain one electron, and atom Y needs to gain six electrons.

Writing the Formula of the Compound:
To form a compound, atom X will donate one of its valence electrons to atom Y. As a result, atom X will have a stable configuration with six valence electrons (similar to a noble gas), and atom Y will have a stable configuration with eight valence electrons (octet rule). The formula of the compound formed between atom X and atom Y will be XY.

Determining the Type of Bond Formed:
The type of bond formed between atom X and atom Y can be determined by comparing their electronegativities. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond.

If the electronegativity difference between atom X and atom Y is very large, an ionic bond is formed. In an ionic bond, one atom completely transfers its valence electrons to the other atom, resulting in the formation of ions. However, in this case, the electronegativity difference is not large enough to form an ionic bond.

If the electronegativity difference between atom X and atom Y is moderate, a covalent bond is formed. In a covalent bond, atoms share their valence electrons to achieve a stable electron configuration. Since atom X donates one electron to atom Y, they share the electron pair, forming a covalent bond.

Therefore, the compound formed between atom X and atom Y is most likely to have a covalent bond.

Summary:
- The compound formed between atom X and atom Y is represented by the formula XY.
- The bond formed between atom X and atom Y is most likely to be a covalent bond.
- Atom X donates one electron to atom Y to achieve a stable electron configuration.
- Atom X has seven valence electrons and atom Y has two valence electrons.
- By sharing the electron pair, atom X achieves a stable configuration with six valence electrons, and atom Y achieves a stable configuration with eight valence electrons.

MgCl2 .Ionic bond is formed here