Gold – Atomic Number – Au

Atomic Number of Gold

Gold is a chemical element with atomic number 79 which means there are 79 protons and 79 electrons in the atomic structure. The chemical symbol for Gold is Au.

Proton Number - Atomic NumberThe atom consist of a small but massive nucleus surrounded by a cloud of rapidly moving electrons. The nucleus is composed of protons and neutrons. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs. In a neutral atom there are as many electrons as protons moving about nucleus. It is the electrons that are responsible for the chemical bavavior of atoms, and which identify the various chemical elements.

See also: Atomic Number – Does it conserve in a nuclear reaction?

Atomic Number and Chemical Properties

Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. The chemical properties of the atom are determined by the number of protons, in fact, by number and arrangement of electrons. The configuration of these electrons follows from the principles of quantum mechanics. The number of electrons in each element’s electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. In the periodic table, the elements are listed in order of increasing atomic number Z.

It is the Pauli exclusion principle that requires the electrons in an atom to occupy different energy levels instead of them all condensing in the ground state. The ordering of the electrons in the ground state of multielectron atoms, starts with the lowest energy state (ground state) and moves progressively from there up the energy scale until each of the atom’s electrons has been assigned a unique set of quantum numbers. This fact has key implications for the building up of the periodic table of elements.

Periodic Table of Elements
1
H

Hydrogen

Nonmetals

2
He

Helium

Noble gas

3
Li

Lithium

Alkali metal

4
Be

Beryllium

Alkaline earth metal

5
B

Boron

Metalloids

6
C

Carbon

Nonmetals

7
N

Nitrogen

Nonmetals

8
O

Oxygen

Nonmetals

9
F

Fluorine

Nonmetals

10
Ne

Neon

Noble gas

11
Na

Sodium

Alkali metal

12
Mg

Magnesium

Alkaline earth metal

13
Al

Aluminium

Post-transition metals

14
Si

Silicon

Metalloids

15
P

Phosphorus

Nonmetal

16
S

Sulfur

Nonmetal

17
Cl

Chlorine

Nonmetal

18
Ar

Argon

Noble gas

19
K

Potassium

Alkali metal

20
Ca

Calcium

Alkaline earth metal

21
Sc

Scandium

Transition metals

22
Ti

Titanium

Transition metals

23
V

Vanadium

Transition metals

24
Cr

Chromium

Transition metals

25
Mn

Manganese

Transition metals

26
Fe

Iron

Transition metals

27
Co

Cobalt

Transition metals

28
Ni

Nickel

Transition metals

29
Cu

Copper

Transition metals

30
Zn

Zinc

Transition metals

31
Ga

Gallium

Post-transition metals

32
Ge

Germanium

Metalloids

33
As

Arsenic

Metalloids

34
Se

Selenium

Nonmetal

35
Br

Bromine

Nonmetal

36
Kr

Krypton

Noble gas

37
Rb

Rubidium

Alkali metals

38
Sr

Strontium

Alkaline earth metals

39
Y

Yttrium

Transition metals

40
Zr

Zirconium

Transition metals

41
Nb

Niobium

Transition metals

42
Mo

Molybdenum

Transition metals

43
Tc

Technetium

Transition metals

44
Ru

Ruthenium

Transition metals

45
Rh

Rhodium

Transition metals

46
Pd

Palladium

Transition metals

47
Ag

Silver

Transition metals

48
Cd

Cadmium

Transition metals

49
In

Indium

Post-transition metals

50
Sn

Tin

Post-transition metals

51
Sb

Antimony

Metalloids

52
Te

Tellurium

Metalloids

53
I

Iodine

Nonmetal

54
Xe

Xenon

Noble gas

55
Cs

Caesium

Alkali metals

56
Ba

Barium

Alkaline earth metals

57-71

 

Lanthanoids

 

72
Hf

Hafnium

Transition metals

73
Ta

Tantalum

Transition metals

74
W

Tungsten

Transition metals

75
Re

Rhenium

Transition metals

76
Os

Osmium

Transition metals

77
Ir

Iridium

Transition metals

78
Pt

Platinum

Transition metals

79
Au

Gold

Transition metals

80
Hg

Mercury

Transition metals

81
Tl

Thallium

Post-transition metals

82
Pb

Lead

Post-transition metals

83
Bi

Bismuth

Post-transition metals

84
Po

Polonium

Post-transition metals

85
At

Astatine

Metalloids

86
Rn

Radon

Noble gas

87
Fr

Francium

Alkali metal

88
Ra

Radium

Alkaline earth metal

89-103

 

Actinoids

 

104
Rf

Rutherfordium

Transition metal

105
Db

Dubnium

Transition metal

106
Sg

Seaborgium

Transition metal

107
Bh

Bohrium

Transition metal

108
Hs

Hassium

Transition metal

109
Mt

Meitnerium

 

110
Ds

Darmstadtium

 

111
Rg

Roentgenium

 

112
Cn

Copernicium

 

113
Nh

Nihonium

 

114
Fl

Flerovium

 

115
Mc

Moscovium

 

116
Lv

Livermorium

 

117
Ts

Tennessine

 

118
Og

Oganesson

 

57
La

Lanthanum

Lanthanoids

58
Ce

Cerium

Lanthanoids

59
Pr

Praseodymium

Lanthanoids

60
Nd

Neodymium

Lanthanoids

61
Pm

Promethium

Lanthanoids

62
Sm

Samarium

Lanthanoids

63
Eu

Europium

Lanthanoids

64
Gd

Gadolinium

Lanthanoids

65
Tb

Terbium

Lanthanoids

66
Dy

Dysprosium

Lanthanoids

67
Ho

Holmium

Lanthanoids

68
Er

Erbium

Lanthanoids

69
Th

Thulium

Lanthanoids

70
Yb

Ytterbium

Lanthanoids

71
Lu

Lutetium

Lanthanoids

89
Ac

Actinium

Actinoids

90
Th

Thorium

Actinoids

91
Pa

Protactinium

Actinoids

92
U

Uranium

Actinoids

93
Np

Neptunium

Actinoids

94
Pu

Plutonium

Actinoids

95
Am

Americium

Actinoids

96
Cm

Curium

Actinoids

97
Bk

Berkelium

Actinoids

98
Cf

Californium

Actinoids

99
Es

Einsteinium

Actinoids

100
Fm

Fermium

Actinoids

101
Md

Mendelevium

Actinoids

102
No

Nobelium

Actinoids

103
Lr

Lawrencium

Actinoids