`"X"` and `"Y"` are isobars with mass numbers `"40"`. If `"X"` has `"19"` protons where `"Y"` has `"20"` protons,the number of neutrons in `"X"` is

Which of the followig sepcies has less number of protons than the number of neutrons?

Which of the following has an equal number of neutrons and protons?

Structures of nuclei of three atoms A ,B and C are given belo 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? (1) A and B are isotopes; A and C are isobars (2) A and C are isotopes; B and C are isobars (3) A and C are isotopes; A and B are isobars (4) B and C are isobars; A and B are isotopes.

The number of protons , electrons and neutrons in tritium are