CHAPTER 2 : THE STURUCTURE CHAPTER 2 : THE STURUCTURE OF THE ATOMOF THE ATOM

2.3 Isotopes & Their Importance2.3 Isotopes & Their Importance

2.4 The Electronic Structure of an 2.4 The Electronic Structure of an AtomAtom

At the end of this lesson, you should be able to:At the end of this lesson, you should be able to:

1.1. State the State the meaning of isotopesmeaning of isotopes..

2.2. List List 3 examples of elements3 examples of elements with with isotopes.isotopes.

3.3. Determine the Determine the number of subatomic number of subatomic particlesparticles of isotopes. of isotopes.

4.4. Justify the Justify the uses of isotopesuses of isotopes in daily in daily life.life.

2.3 Isotopes & Their Importance

ISOTOPES

Atoms of the same element with different number of neutrons

How about the Nucleon No. & Proton No.???

ISOTOPES

Atoms of the same element with different number of neutrons

Isotopes of Hydrogen:

Isotopes have the SAME PROTON NO. but DIFFERENT NUCLEON NO.

Some examples of isotopes of elements:

Give another example of isotopes of an element

Uses of Isotopes

Cobalt-60

Used in radiotherapy for the treatment of cancer Sodium-24

Used to detect leaks in pipes carrying gas

Carbon-14

Used in carbon dating to estimate the age of fossils &

artifacts

Oxigen-18

Is a biological tracer used in the studies of

photosynthesis in plant

Phosphorus-32

Used in fertilizers to study the metabolism of

phosphorus in plant

GROUP ASSIGNMENT

Describe the usage of isotopes in various fields:

1. Medicine

2. Industry

3. Agriculture

4. Archeology

Please state your references…

1.1. Describe the Describe the electron arrangementselectron arrangements of of atoms of elements with the proton atoms of elements with the proton numbers of 1 to 20.numbers of 1 to 20.

2.2. Draw electron arrangementDraw electron arrangement of an atom of an atom in an element.in an element.

3.3. State the State the meaning of valence electronsmeaning of valence electrons..

4.4. Determine the Determine the number of valence number of valence electronselectrons from the electron from the electron arrangement of an atom.arrangement of an atom.

At the end of this lesson, you should be able to:At the end of this lesson, you should be able to:

2.4 The Electronic Structure of an Atom

ELECTRONIC CONFIGURATION

The arrangement of electrons around the nucleus in the shells of an atom

1st shell : max. 2e

2nd shell : max. 8e

3rd shell : max. 8e

Electrons

Nucleus

Valence electrons : e in outermost shell

Electronic Configuration of some Elements

What have you learnt today?

• Meaning of ISOTOPES• Meaning of ELECTRONIC

CONFIGURATION• Maximum number of electrons in the

1st shell, 2nd shell and 3rd shell• Meaning of VALENCE ELECTRONS