Chemistry
Define the following terms:
(a) Atomic number
(b) Mass number
(c) Nucleons
(d) Valence shell
Answer
(a) The number of protons present in the nucleus of the atom of an element is called its atomic number.
(b) The sum of the number of protons and the number of neutrons present in the nucleus of the atom of an element is called the mass number of that element.
(c) The protons and neutrons are collectively called as nucleons.
(d) The outermost shell of an atom is known as its valence shell or valence orbit.
Related Questions
Match the following :
Column A Column B (a) John Dalton (i) Electronic configuration (b) J.J. Thomson (ii) Discovery of nucleus (c) Maharishi Kannada (iii) Atomic theory (d) James Chadwick (iv) Plum-pudding atomic model (e) Ernest Rutherford (v) Paramanus (j) Neil Bohr (vi) Neutrons Name the following :
(a) The subatomic particle with negative charge and negligible mass.
(b) Protons and neutrons present in the nucleus.
(c) The electrons present in the outermost shell.
(d) Arrangement of electrons in the shells of an atom.
(e) The number of protons present in the nucleus of an atom.
(f) The sum of the number of protons and neutrons of an atom.
(g) Atoms of same element with same atomic number but a different mass number.
(h) The smallest unit of an element which takes part in a chemical reaction.
(i) The particle which is not present in an atom of hydrogen.
Name three fundamental particles of an atom. Give their symbol with charge on each particle.
Which fundamental particle is present in anode rays ? Why anode rays are also called as canal rays.