Define the following terms :
(a) atomic number, and (b) mass number.

Define atomic number and mass number of an atom.

Define the following terms (a) tranquilizers (b) antiseptic

Complete the following sentences : (a) The mass number and atomic number of an element are not changed when it emits …………………. (b) The atomic number of a radioactive element is not changed when it emits …………………………… (c ) During the emission of a beta particle, the ................. number remains same.

Define the following: Atomic number

What is nucleus of an atom ? Compare its size with that of the atom. Name its constitutents. How is the number of these constituents determined by the atomic number and mass number of the atom ?

Define the following terms : (a) Atoms (b) Molecules (c) Radicals (d) Valency (e) Periodic table

Write the complete symbols for the nuclei with (i) atomic number 17 and mass number 35 (ii) atomic number 8 and mass number 16 (iii) atomic number 26 and mass number 55 (iv) atomic number 2 and mass number 4.

Atom with the same atomic number and different mass numbers are called

Differentiate between the atomic number and the mass number.

How many electrons, protons, and neutrons are there in an atom of atomic number 11 and mass number 24?