Atomic number and atomic mass of elements of periodic table

The atomic number and mass number

The atomic number is the number of protons present in the nucleus of an atom which represents the chemical properties and position of such element in the periodic table. Thus the properties of an element dictated by its atomic number or number of its electron.

Electron holds the key to the chemical world because the chemical properties of the element understand by its electronic structure.

But the number of protons and the number of neutrons together called the mass number of an element.

Mass number = number of electrons + number of protons

How to calculate the atomic mass unit?

The atomic weight of an element is a number that says how much heavy an atom of an element compared to one-twelfth of an atom of the carbon-12 isotope. But the gram atomic weight of an element is the weight in gram.

Atomic mass unit (amu) is exactly the one-twelfth of the mass of a carbon-12 atom. Thus the mass of an atom expressed in amu which numerically equal to its atomic weight on the carbon-12 scale.

1 amu = (12/6.023) × (1/12) × 10-23 gm
= 1.6603 × 10-24 gm

Chemical Bonding

The atomic number of s block elements

Element Symbol Atomic number Atomic mass
Hydrogen H 1 1.008
Lithium Li 3 6.940
Sodium Na 11 22.997
Potassium K 19 39.100
Rubidium Rb 37 85.480
Cesium Cs 55 132.91
Francium Fr 87 223
Element Symbol Atomic number Atomic mass
Beryllium Be 4 1.008
Magnesium Mg 12 6.940
Calcium Ca 20 22.997
Strontium Sr 38 87.63
Barium Ba 56 137.36
Radium Ra 88 226.05

The atomic mass of p block elements

Element Symbol Atomic number Atomic mass
Boron B 5 10.82
Aluminum Al 13 26.98
Gallium Ga 31 69.72
Indium In 49 114.76
Thallium Tl 81 204.39
Carbon C 6 12.01
Silicon Si 14 28.09
Germanium Ge 32 72.60
Tin Sn 50 118.70
lead Pb 82 207.21
Nitrogen N 7 14.008
Phosphorus P 15 30.975
Arsenic As 33 74.91
Antimony Sb 51 121.76
Bismuth Bi 83 209.00
Oxygen O 8 16.00
Sulfur S 16 32.066
Selenium Se 34 78.96
Tellurium Te 52 127.61
Polonium Po 84 210
Fluorine F 9 19.00
Chlorine Cl 17 35.457
Bromine Br 35 79.916
Iodine I 53 126.91
Astatine At 85 210

Electronic Structure of an atom

Parts of an atom

Global Enviourment

The atomic number of noble gases

Element Symbol Atomic number Atomic mass
Helium He 2 4.003
Neon Ne 10 20.183
Argon Ar 18 39.944
Krypton Kr 36 83.80
Xenon Xe 54 131.3
Radon Rn 86 222

Equlibium Point

Atomic number of d block elements

The atomic number and mass number
Name, symbol, and atomic number