Questions

It is a Postbox or a Mailbox which contains thousands of letters or mails or messages.

The name given to the bond between water molecules is a hydrogen bond. These bonds occur between the slightly negative oxygen of one water molecule and the slightly positive hydrogen of another water molecule. Hydrogen bonding gives water special physical properties.

The differences in electronegativity between hydrogen and oxygen lead to an unequal sharing of electrons. Electronegativity measures how strongly an atom attracts electrons. Oxygen, with its higher electronegativity, pulls on the shared electrons more, giving the oxygen atom a partial net negative charge. The shared electrons spend less time with the hydrogen atoms; therefore, the hydrogen regions of water have partial positive charges.

Magma is injected into surrounding rock forming an igneous intrusive.

Actually it is a plutonic formation in which magma present beneath Earth surface deforms the shape of rocks present above it
 

A computer program is a set of instructions i.e algorithm that are to be executed to complete a task.

Simhika