Hydrogen has three isotopes written as: H 1 1 , H 1 2 , H 1 3 Explain why these isotopes have almost identical chemical properties.

The chemical properties of isotopes of hydrogen are similar because they have the same number of protons, which means that they have the same number of electrons which are responsible for the same chemical nature of the isotopes.

Hydrogen has three isotopes written as: H 1 1 , H 1 2 , H 1 3 Explain why they are electrically neutral.

All the isotopes of hydrogen have 1 electron (negative charge) and 1 proton (positive charge). That is, their net charge will be zero. Therefore, they are electrically neutral. Isotopes differ only in number of neutrons.

Given that the percentage abundance of the isotope Ne 10 20 is 90 % and that of the isotope Ne 10 22 is 10 % , calculate the average atomic mass of neon.

Isotopes of neon which are Ne 10 20 and Ne 10 22 have 90 % and 10 % abundance respectively and their masses are 20 and 22 respectively. Therefore, the average atomic mass of neon can be calculated as, Atomic mass of Ne 10 20 × Its abundance 100 + Atomic mass of Ne 10 22 × Its abundance 100 i.e, 20 × 90 100 + 22 × 10 100 = 1800 100 + 220 100 = 18 + 2 . 2 = 20 . 2 u