Uses of Radioisotope in Daily Life

The history development of atomic models

Atomic Structure & Electron Arrangment

Study Visit to Malaysia Nuclear Agency

On 6 Mac 2013,  my colleague Ms Wan Eliza Wan Ali and I together with 39 students have visited Malaysian Nuclear Agency which is situated in Bangi. During the visit, we are briefed on the nuclear technology development in Malaysia. Later we went to MINTec-Sinagama plant. The plant is working on irradiation of herbs, foods &b medical supplies by using cobalt-60.

A 3 hours study trip indeed have given students and teachers a deeper understanding on uses of radioisotopes in Malaysia context. 

Determine the Physical State of A Substance at a Given Temperature

SPM 2012 Paper 1 Question 25  

1. The melting point and boiling point of  V and W are lower than 100⁰C. Both exist as solid at 100⁰C. 
2. The melting point of  X is lower than 100⁰C. The boiling point of X is higher than 100⁰C.  It exists as liquid in room temperature.
3. Both the melting point and boiling point of Y are lower than 100⁰C.  It exists as gas in room 100⁰C. 

The correct answer is : C

Common Sources of Radiation Used in Malaysia

Medical Field

Widely used in Nuclear Medicine, radiology & Radiotherapy, for diagnosis purposes & medical research. 
Common radioisotopes used : Technitium-99, Cobalt-60, Cesium-137, Iodine & Radium 226

In Industry

Used in industrial application such as gauging, oil logging, industrial radiography, analyytical purposes for minerals & soil samples, quality assuarance for electronic componenets & tracer 
technique applications. 
Common radioisotopes used : Americium-241, Berryllium-9, Cobalt-60, Cesium-137, Stronitium-90, Iridium-192, Argon-41, Kripton-85, Sodium-24.

In Research

Mostly for research activities in agriculture, medicine & nuclear sciences. 
Common radioisotopes used : Phosphorus-32, Technitium-99, Cobalt-60, Cesium-137, Gold-198.

Source : Atomic energy Licensing Board, Malaysia

My Atomic Structure

After studying proton number, nucleon number, electron arrangment in the classroom in Chapter 2, Form 4 students are asked to construct models to show the  atomic structure for different elements.

Sublimation of Dry Ice

Dry ice is the common name for the solid form of carbon dioxide.

It undergoes sublimation at room temperature. 

Uses of Dry Ice:

• keep ice cream frozen
• as a refregerants in pharmaceutical, blood and organ shipment

When dry ice sublimates in the glove, the carbon dioxide gas released filled up the glove.

My students during K2M 2011 at National Science Centre

Atomic Structure of Sodium Atom

How to describe atomic structure of sodium atom?

• Proton number of sodium is 11.
• Nucleon number of sodium is 23.
• Sodium atom has 12 neutrons.
• Sodium atom has 11 protons.
• Protons and neutrons are found in the nucleus of the sodium atom.
• Sodium atom has 11 electrons. The electrons are moving around the nucleus in their shells.
• Electron arrangement of sodium atom is 2.8.1.
• Sodium atom has 1 valence electrons.

Similar questions was found in SPM 2006 & SPM 2007. For more details, click here.

Scientists' Contribution towards Development of Atomic Structure

1. J.J. Thomson discovered electron.
2. Ernest Rutherford discovered the proton
3. James Chadwick discovered the neutron.

We get to know more about an atom thanks to their effort.

In your opinion, how does an atom look like? How about a carbon atom?

Please respond  by leaving your comments & names.

Determing Melting Point

Example of Essay Question:
Solid Z has a melting point of 65^oC.  Describe a laboratory experiment to determine the melting point of Z. Your answer should show how the melting point of Z is determined.

Requirement of the Question 

a) Procedure and diagram
b) A table showing time and temperature.
c) Sketch a graph temperature of substance Z against time.
d) Show how melting point of substance can be obtained from the graph.

Definition of Isotopes

What's the definition of the isotopes? The video clip shows isotopes of hydrogen.


Sound simple, right? After watching the video clip, I hope you can identify some key words to define isotopes.

Isotopes are atoms that have the same number of protons but different number of neutrons. or

atoms that have the same proton number but different nucleon number.

My students used to give their definition of isotopes as follows:

1. same number of proton but different number of neutrons
2. same proton number but different neutron number.

Sadly, their answers are not considered as a complete definition., The first answer didn't mention the most important keyword: atoms. The second answer used "neutron number" which is incorrect term.

Some examples of isotopes :

1. carbon-12, carbon-13, carbon-14;
2. oxygen-16, oxygen-17, oxygen-18;
3. chlorine-35, chlorine-37.
4. chlorine-35 and chlorine-37.

Isotopes are widely in our daily life. Can you give some examples of isotopes used in medicine, industry, science and archeology?
In fact, the similar question turned out in SPM 2005.

Atomic bomb on Hiroshima and Nagasaki

Today Hiroshima marked the 65^th anniversary of atomic bomb attack. Some chemistry related facts about the making of atomic bomb:

• The Hiroshima bomb which is called "Little Boy" used Uranium-235.
• The Nagasaki bom, "Fat Man" made of Plutonium-239.

More information related to the atomic bomb & World World II, click here.

Atomic Model

An atom consists of three types of subatomic particles:

• proton
• neutron
• electrons

Each subatomic particle have different properties. Students are advised to know their differences in terms of relative charge, relative mass and location in an atom.

In Paper 2 SPM 2006,  students are asked

• to compare the relative mass and the charge of two of the subatomic particles[4 marks].
• describe fully the atomic structure of lithium[6 marks].
• draw the structure of an atom of sodium or potassium[7 marks].

In Paper 2 SPM 2007, students are asked to

• describe and the atomic structure of hydrogen[4 marks].

Kinetic Theory of Matter

   That's basic chemistry. But when I looked at my students' work in explaining kinetic theory of matter, thousands of questions popped up in my mind. How much do my students understand Kinetic Theory of Matter? It seems that it's such an abstract concept for them.  If I'm not mistaken, a student is exposed to this theory when they were studying Form 1 Science.

  Kinetic Theory of Matter explains that matter consists of tiny and discrete particles, which are always moving.
 
  Perhaps the theory is quite microscopic. We cannot feel it, see it or imagine it. But, there were some phenomena which can prove the Kinetic Theoryf of Matter. For example,

• Brownian movement.
• Diffusion in solid, liquid and gas.
• Changing of state of matter when heat is absorbed/released

  I'll post more how above examples can prove the Kinetic Theory of Matter.

Heating Curve

The graph shows the heating curve of element Y.

Describe the graph in terms of state of matter, particle arrangements and changes in energy.

From t₀ – t₁

1 In liquid state

2 Particles are arranged closed to each other but not closely packed together

3 Particles are not arranged in order

4 Energy increases

From t₁ – t₂

5 In liquid and gas state

6 Some particles are close to each but some are far apart

7 Particles are not arranged in order

8 Energy remains constant//does not increase

From t₂ – t₃

9 In gas state

10 particles are far apart from each other

11 Particles are not arranged in order

12 Energy increase