General
✓✗Outer most shell of an atom is called
- Last shell
- Penultimate shell
- Valence shell
- Peripheral shell
General
✓✗The radioactive isotope used as a fuel in reactors of nuclear power plants is
- Iodine -131
- Cobalt -60
- Uranium -235
- All of these
General
✓✗Rutherford’s alfa particle scattering experiment led to the discovery of
- Neutrons
- Nucleus
- Electrons
- Protons
General
✓✗Which one of the following is not an isotope of Hydrogen?
General
✓✗An element has atomic number 13, its electronic configuration will be
- 2, 6, 5
- 2, 7, 4
- 2, 8, 3
- 2, 8
General
✓✗Which one of the following shows both electrovalency and covalency?
- Chlorine
- Oxygen
- Nitrogen
- All of these
General
✓✗Atomic mass of chlorine is in fractions (35.5 u) because
-
The percentage of
is 75% and is 25%
-
The percentage of
is 75% and is 25%
-
Both
and are 50% each
-
The percentage of
is 90% and is 10%
General
✓✗Isotopes are atoms of same element having
- same mass number but different atomic number
- same atomic number but different mass number
- same atomic number and same mass number
- different atomic number and different mass number
General
✓✗Third energy level can hold maximum of
- 2 electrons
- 8 electrons
- 18 electrons
- 32 electrons
General
✓✗Valency of a metal is equal to
- Number of valence electrons
- Number of electrons
- Number of shells
- Atomic number