Mrs. Eleanor Roosevelt, (United States) holding a Declaration of Human Rights. Â© UN Photo. The formal inception of Human Rights Day dates from 1950, after the Assembly passed resolution 423 (V) inviting all States and interested organizations to adopt 10 December of each year as Human Rights Day.he formal inception of Human Rights Day dates from 1950, after the Assembly passed resolution 423 (V) inviting all States and interested organizations to adopt 10 December of each year as Human Rights Day.
The number of protons in the nucleus of the atom is equal to the atomic number (Z). The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).
Isotopes are atoms which have the same atomic number but different mass numbers. They have the same number of protons but different numbers of neutrons.The number of neutrons in an atom can vary within small limits. For example, there are three kinds of carbon atom 12C, 13C and 14C. They all have the same number of protons, but the number of neutrons varies.