Question

Define :atomic number,mass number,calnal rays,isobars,isotopes

Answer 1

An atomic mass (symbol: ma) is the mass of a single atom of a chemical element. It includes the masses of the 3 subatomic particles that make up an atom: protons, neutrons and electrons. ... 1 atomic mass unit is defined as 1/12 of the massof a single carbon-12 atom.

MASS NUMBER - sum of numbers of proton and nutron.
ISOBAR - Isobars are the atoms of different elements having different atomic number but same mass number.
ISOTOPES - Isotopes have the same atomic number, while isobars have the same atomic mass. Isotopes : Isotopes are atoms that have same atomic number but different mass numbers. Isotopes have the same atomic number because the number of protons inside their nuclei remains the same.