2.4 Atoms

What is the smallest particle of an element that can exist?

• Cell

• Molecule

• Atom

• Compound

Atoms are tiny, with a diameter of about ...............................

• 0.000 000 01 mm

• 0.000 000 01 cm

• 0.000 01 cm

• 0.000 000 01 m

Silicon is an element used in tiny electric circuits in every .................................

(choose the best answer)

• computer.

• TV.

• phone.

• All choices are correct.

How many atoms side by side would stretch one centimetre?

• 100 million

• 1 million

• 1 billion

• 10 million

A substance that is made up of particles called atoms, which cannot be split into other substances.

• A molecules.

• An atoms.

• A compounds.

• An element.

How many types of atoms are there approximately?

• 150

• 200

• 118

• 50

Similar elements have ..................... properties as they are made from the same atoms.

• different.

• similar.

Different elements have different properties, because different ............................... have different properties.

• atoms

• compounds

• molecules

• mixtures

What is a model in science?

• A type of atom.

• An idea that explains observations.

• A type of compound.

• A type of element.

The scientific model shows that every element has its own type of atom.

• True.

• False.