Atoms & Molecules

19

description

 

Transcript of Atoms & Molecules

Page 1: Atoms & Molecules
Page 2: Atoms & Molecules

Atom and Molecules

Prepared By:

Fahad And Arsalan

Page 3: Atoms & Molecules
Page 4: Atoms & Molecules

• An atom is the smallest unit that maintains the characteristics of an element

– Nucleus- The center of the atom, contains protons and neutrons

– Electron Cloud –Region surrounding the nucleus containing the electrons

ATOM

Page 5: Atoms & Molecules

The Nucleus Proton- A positively charged sub-atomic particle (+).The number of protons is

the same as the atomic number

Li3

7 The atomic massThe atomic mass

The Atomic Symbol

Neutrons– A sub-atomic particle in the nucleus. Neutron do not have a charge (0)

Page 6: Atoms & Molecules

The Electron Cloud

• Electrons-• The number of electrons equals the number of protons• Sub-atomic particle with a negative charge (-)• Mass of an electron is negligible• Electrons behave as if in a 3-D orbit

• Valence Electrons– The outer most electrons– Valence electrons are responsible for bonding

Page 7: Atoms & Molecules

Bohr Model• The first shell can have

2 electrons• The second can

have 8 electrons

Page 8: Atoms & Molecules

Shells and the Electron Cloud

Page 9: Atoms & Molecules

Let’s look at a few elements…

Hydrogen 1= Proton 1= electron

Page 10: Atoms & Molecules

Let’s look at a few elements…

Lithium 3=protons 4=neutrons3=electrons

Page 11: Atoms & Molecules

Let’s look at a few elements…

Argon18=protons 22=neutrons

18=electrons

Page 12: Atoms & Molecules

Isotopes Atoms of the same element with different number

of neutrons

Isotopes of Hydrogen

Page 13: Atoms & Molecules

Molecules

Page 14: Atoms & Molecules

Molecules

A molecule is defined as a stable neutral group of at least two atoms in a definite arrangement held together by very strong chemical bonds .

It can also be defined as a unit of two or more atoms held together by covalent bonds.

Page 15: Atoms & Molecules

Types Of bonding

Ionic Bond:

Ionic bonds are formed when atoms become ions by gaining or losing electrons.

Page 16: Atoms & Molecules
Page 17: Atoms & Molecules

Covalent Bond:

Covalent bonds form when atoms share electrons. Since electrons move very fast they can be shared, effectively filling or emptying the outer shells of the atoms involved in the bond. Such bonds are referred to as electron-sharing bonds.

Page 18: Atoms & Molecules

Guess What its Video Time

Page 19: Atoms & Molecules

The End

Now Please Wake Up for Clapping.