Questions

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

Most people say "Yes" and do not add more to it. Use this opportunity to market yourself and express interests and activities that are aligned with job role you are applying.

This orbital velocity at the moon is less because orbital velocity = rg

where 'r ' is the orbital radius. i.e the distance of the body from the center of the earth and 'g' is the acceleration due to gravity on the body in question. In the case of the moon, both r and g are less than in the case of the earth.

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.