Atom

Hello Students,

Today we are going to cover the topic “Atom”.

What we are going to cover in this article:

1. What is atom?

2. Who discovered the atom?

3. Structure of atom.

So, first of all what is atom and where it exist.

Atoms are the basic units of matter.

Who discovered it?

The idea that matter is made up of discrete units is a very old idea, appearing in many ancient cultures such as Greece and India. The word "atom" was coined by the ancient Greek philosophers Leucippus and his pupil Democritus.

The constituents of the atom.

The constituents of the atom are protons, neutrons and electrons. The protons and neutrons (nucleons) are found in the nucleus of atoms. The nucleus of an atom is surrounded by empty space in which there are electrons.

Particle: Proton

Relative Mass: 1

Relative Charge: +1

Charge/C: 1.674929 x 10^-19 

Mass/kg: 1.674929 x 10^-27

Particle: Neutron

Relative Mass: 1

Relative Charge: Neutral

Charge/C: 0

Mass/kg: 1.674929 x 10^-27

Particle: Electron

Relative Mass: 0.0005

Relative Charge: -1

Charge/C: -1.674929 x 10^-19

Mass/kg: 9.1×10^-31

Atoms are described by their proton number (Z), which is the number of protons they contain.

Isotopes are  atoms which have the same number of protons but different numbers of neutrons.  Isotopes are all atoms of the same element. We can see below that uranium-238 still has 92 protons  but it now has 146 neutrons so its nucleon number is now 238.

Isobars are atoms of different Chemical elements that have the same number of nucleons.

Medical Uses of Isotopes

isotopes are widely used in medicine to diagnose and treat illnesses. Isotopes have extensive applications in bio-medical research and other fields like chemistry, physics, biology, and geo-sciences.There are many radioisotopes which are mainly used in the treatment of hazardous diseases such as cobalt-60 ( Co-60) is  used to damage  the  cancer cells without surgery , that is known as radiotherapy.

Uses of Isotopes in Agriculture

They are used to cause mutation in insects that make them sterile or to cause death. This method helps in pest control in agriculture.

Uses of isobar

an isobar of iodine is used in the treatment of goitre.

an isobar of cobalt is used in treatment of cancer.

an isobar of uranium is used as a nuclear reactor

Atomic Number

The atomic number (symbol Z) of a chemical element is the number of protons found in the nucleus of an atom.

Element	Symbol	Atomic Number	Atomic Mass	Number of Protons	Number of Neutrons
Hydrogen	H	1	1	1	0
Helium	He	2	4	2	2
Lithium	Li	3	7	3	4
Beryllium	Be	4	9	4	9
Boron	B	5	11	5	6
Carbon	C	6	12	6	6
Nitrogen	N	7	14	7	7
Oxygen	O	8	16	8	8
Fluorine	F	9	18	9	9
Neon	Ne	10	20	10	20
Sodium	Na	11	23	11	12
Magnesium	Mg	12	24	12	12
Aluminum	Al	13	27	13	14
Silicon	Si	14	28	14	14
Phosphorous	P	15	31	15	16
Sulphur	S	16	32	16	16
Chlorine	Cl	17	35	17	16
Argon	Ar	18	40	18	22
Potassium	K	19	39	19	20
Calcium	Ca	20	40	20	20

Atomic Mass

It is approximately equivalent to the sum of protons and neutrons of the atom.