What electron configurations do atoms usually achieve by sharing electrons to form covalent bonds?

Explanation: The atoms attain the configuration of inert gas by sharing electrons.

Lets take an example of HCl,

Atomic number of H is 1 and it has only 1 valance electron. whereas atomic number of chlorine is 17 and it has 7 valance electron.

When hydrogen atom combine with chlorine atom then they share electrons through covalent bonding in order to complete their octet.

According to figure,

Electronic configuration of H = 1

Electronic configuration of Cl = 2,8,7

Now, after share of electron

Electronic configuration of H = 2

Electronic configuration of Cl = 2,8,8

Hence, we can conclude that when atoms share electrons then their octet gets complete and atoms achieve noble gas electronic configuration.

magnitude and direction

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.