Structure and Bonding

Atomic Structure
Proton
RM=1 RC=+1
Neutron
RM=1 RC=0
Electron
RM=1/1836 RC=-1

Nucleus contains protons and neutrons (together known as nucleons). The nucleus makes up almost all the mass of the atom because electrons weigh so little.

No of Protons=atomic number
No of protons and neutrons= Atomic Mass Number
No of protons=no of electrons
No of neutrons=atomic mass-atomic number

Isotopes
Varying numbers of neutrons makes absouloutely no diference to the chemical reactions of the element.
Isotopes are atoms which have the same amount of protons but different amount of neutrons.

Atoms are electrically neutral so the positiveness of the Protons are balanced by the negativeness of the Electrons eg. Chlorine has 17 protons so it must have 17 electrons

Ionic Bonding
Sodium (2,8,1) has 1 electron more than a stable noble gas structure (2,8). If it gave away that electron it would become more stable.
Chlorine (2,8,7) has 1 electron short of a stable noble gas structure (2,8,8). If it could gain an electron from somewhere it too would become more stable.
The answer is obvious. If a sodium atom gives an electron to a chlorine atom, both become more stable.The sodium has lost an electron, so it no longer has equal numbers of electrons lhhhhhhhhhhhhhhhhhhhhlhand protons. Because it has one more proton than electron, it has a charge of 1+. If electrons are lost from an atom, positive ions are formed.
The chlorine has gained an electron, so it now has one more electron than proton. It therefore has a charge of 1-. If electrons are gained by an atom, negative ions are formed.
Ionic Bonding has to be between a metal and a gas
Covalent Bonding
Covalent chemical bonds involve the sharing of a pair of valence electrons by two atoms, in contrast to the transfer of electrons in ionic bonds. Such bonds lead to stable molecules if they share electrons in such a way as to create a noble gas configuration for each atom.
Polar Covalent Bonding
Covalent...