Lesson #16 Isotopes and Isotopes of hydrogen

Isotopes and Isotopes of hydrogen:

Since both the atom have same atomic number, they must be the atoms of the same element and are called isotopes. The word isotopes was first used by soddy.It is a Greek word "isos" mean same" tope " mean place.

Isotopes:

Isotopes are atoms of an elements whose nuclei have same atomic number but different mass number. This is because atoms of an elements can differ in the number of neutrons.

Isotopes of hydrogen:

Hydrogen has three isotopes. hydrogen-1 (protium) has no neutron. Almost all the hydrogen is hydrogen-1. Its symbol is H1. Hydrogen-2 ( deuterium) has one neutron and hydrogen-3 (tritum) has two neutrons. Their symbols are H-2 and hydrogen-3 respectively because hydrogen-1 also known as protium has only one proton, adding a neutron doubles it mass. Protium,/ Hydrogen is a colourless, odourless, and tasteless gas. It is insoluble in water and is high inflammable gas.

Heavy water:

Water that contain hydrogen-2 atoms in the place of hydrogen-1 is called heavy water.

Comparison of ordinary water and heavy water:

Ordinary water:
Melting point / / / 0.00℃
Boiling point / / / 100℃
Density in 25℃ / / / 0.99701g/cm3
Heavy water:
Melting point / / / 3.81℃
Boiling point / / / 101.2℃
Density in 25℃ / / / 1.1044g/cm3