The sum of the number of protons and neutrons in the nucleus of the atom is known as …………...

The atomic number of the atom of an element equals the……….

The mass number of an atom having 13 electrons and 14 neutrons equals ………….

The atomic number of an atom having 6protons in the nucleus is ………….

The chemical symbol of nitrogen atom is …………

All the following atoms have 1 electron in the outermost energy level except …………..

The maximum number of energy levels in the heaviest known atoms is…………………….

All of the following elements are active elements except……

The second energy level in (₇N) atom contains …………electron.

The electrons of potassium atom

( ₁₉K ) are distributed in ………….. energy level.

The third energy level is saturated with ………. Electrons.

The number of electrons that saturates the first four energy level can be calculated fro the relation…………..

Ag is the symbol of …………….

All of the following elements are inactive except……………

The atomic number of an element has 1 electron in (L ) level is …………….

All of the following atoms can take part in the formation of chemical compounds in ordinary conditions except………… atom

The energy of the electron is………………………the energy of the level which it revolves in.

The atom nucleus contains ……………..

…………… are neutral particles in the nucleus.

The nucleus of …………… atom doesn’t contain neutrons

The negative charged particles of negligible mass are ………….

The chemical symbol of magnesium is ……………..