Define molecule of a compound. Give one example.

Define electronegativity.

What is meant by molecular mass?

In what form atoms can exist in an aqueous solution? Give examples.

State the law of conservation of mass. Give one example to illustrate this law.

State the law of constant proportion. Give one example to illustrate this law.

If $10 \mathrm{g}$silver nitrate solution is added to $10 \mathrm{g}$ of sodium chloride solution, then what change in mass would you expect after the reaction? Why?

Dalton's atomic theory postulated that 'Atoms combine in simple whole-number ratio'. What are the postulates of modified Dalton's atomic theory?