Electronic Materials and Devices

1. Welcome To My
Presentation

2. Presented By
Abel Presley Gomes
ID:162-33-3499

3. Topic
Atomic Structure

4. What is atom ?
 Matter is anything that takes up space and has mass.
 All matter is made of atoms.
 Atoms are the building block of matters, sort of how bricks
are the building blocks of houses.

5. Atomic Theory
 All matter is made up of atoms.
 Atoms of an element are identical.
 Each element has different atoms.
 Atoms can engage in a chemical reactions.
 Atoms can neither be created nor be destroyed.
 Atoms are indivisible.
John Dalton
(1776-1884)

6. What is the structure of an atom?
 Electron
Has a negative (-) charge
Found outside the nucleus
Rutherford atom model - electrons are around the
nucleus
Bohr model – electrons are in specific energy levels
called shells

7. Atomic structure of an atom
 Atoms are made of three different types of subatomic
particles called protons, neutrons and electrons.
 Protons and neutrons are found in the nucleus and
they are known as nucleons.
 Nucleus is positively charged because the protons are
positively charged and the neutrons are electrically
neutral.
 Electrons rotate around the nucleus in a certain orbit
called shells, just like planets rotate around the sun.

8. PROTON NUMBER
The number of protons in an atom of an element.
Proton number = Number of Protons

9. NUCLEON NUMBER
The sum of protons and neutrons in an atom element.
Nucleon number = Number of protons + Number of neutrons

10. NUMBER OF NEUTRONS
 The difference between the nucleon number and the proton
number
 A neutral atom has the same number of protons and the
number of electrons
 Different elements have different numbers of protons
Number of neutrons = Nucleon number – Proton number