2.4 Atoms

Natural sciences

Grade 8

Matter: classification

Module 17

Atoms

• We have already mentioned the fact that atoms are the smallest particles in the composition of matter.

But what is the size of an atom and what is it like?

• The diameter of an atom is 0,000 000 001m – which is one millionth of a millimetre!
• When you inflate a balloon, which then seems to contain nothing, you need to consider that it will contain approximately one billion gas atoms (100 000 000 000 000 000 000)!
• One cubic millimetre of table salt (as much as will cover the head of a pin) will contain approximately 70 million atoms!
• If each of the atoms in a grain of sand were the size of the head of a pin, the grain of sand would have a diameter of two kilometres!
• Atoms are rightfully regarded as the building blocks of matter, but there also are subatomic particles, which we know as Protons, Neutrons and Electrons .

Ask your educator for help with drawing the atoms of hydrogen and of oxygen:

Class project

POSTER – Scientists through the ages

• Gather information about scientists like Ernest Rutherford (1911) and Neils Bohr (1913) and their contribution to present-day knowledge of atoms.
• Collect pictures and bring the information you have gathered to the class.
• Work together as groups to produce a poster dealing with scientists through the ages . We’ll be adding other names to the list as we work through the module.

Assessment of class project

Did you collect the information and assemble the poster, honouring scientists through the ages for their efforts?

[LO 1.1; LO 1.2; LO 1.3; LO 3.1]

 Do you know the following? 

There are subatomic particles known as muons, gluons, and gravitons!

There are particles that are smaller than electrons known as quarks and leptons.

Quarks have strange names, like: up , down , strange , as well as up and down

Read more about these strange things, which are the smallest known particles.

Assessment

Learning outcomes 1: Scientific investigations

The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

We know this when the learner:

• is able to plan investigations;
• is able to execute an investigation and collect data;
• is able to evaluate data and communicate findings.

Learning outcomes 3 : Science, society and the environment

The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment.

We know this when the learner:

3.1 is able to show appreciation of science as a human endeavour.

Memorandum

Project