Carbon has __________ isotopes.
Structures of nuclei of three atoms A, B, and C are given below: A has 90 protons and 146 neutrons. B has 92 protons and 146 neutrons. C has 90 protons and 148 neutrons. Based on the above data, which of these atoms are isotopes and which are isobars?
The flame of a Kerosene on lamp (or lantern) has :
(a) single zone
(b) two zones
(c) three zones
(d) four zones