The number of nucleons in an atom is called __________________.
mass number
atomic number
electronic number
neutron number
The number of nucleons(neutrons and protons) in an atom is called mass number.
Multiple Choice Questions
(a) The outermost shell of an atom is known as
(i) valency
(ii) valence electrons
(iii) nucleus
(iv) valence shell
(b) The number of valence electrons present in magnesium is
(i) two
(ii) three
(iii) four
(iv) five
(c) The sub atomic particle with positive charge is
(i) proton
(ii) neutron
(iii) electron
(iv) nucleon
(d) If the atomic number of an atom is 17 and mass number is 35 then number of neutrons will be
(i) 35
(ii) 17
(iii) 18
(iv) 52
(e) The number of electrons in an atom is equal to the number of
(i) protons in a neutral atom
(ii) neutrons in a neutral atom
(iii) nucleons in a neutral atom
(iv) none of the above
(f) The sum of number of protons and number of neutrons present in the nucleus of an atom is called its
(i) mass number
(ii) atomic number
(iii) number of electrons
(iv) all of the above
A neutral atom 'X' has a mass number 12 and atomic number 6. Calculate the number of electrons present in the atom.
If Z is the number of protons and A the number of nucleons, then the number of neutrons in an atom is given by