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).
Atomic number and mass number. The atomic number of an atom is the number of protons it contains. All the atoms of a particular element have the same atomic number (number of protons). The atoms of different elements have different numbers of protons. For example, all oxygen atoms have 8 protons and all sodium atoms have 11 protons. The mass number of an atom is the total number of protons and neutrons it contains.