Grade 8 Science First Written Test

Which of the following describes matter?

• It exists in solid and liquid phases.

• Either have no mass or don’t fill a volume.

• It is made up of small particles called elements.

• It is anything that takes up space and has mass.

What can you infer on the forces of attraction of molecules when solid ice turns to liquid water?

• They lose energy.

• They gain energy.

• The particles get compressed.

• The particles are magnetised.

Which is the smallest particle of matter?

• Atom

• Cell

• Element

• Molecules

You measure exactly 100 millilitres of water in a graduated cylinder. You heat the water to 100 °C and notice that the volume increases to 104 millilitres. Using what you know about the attractions between water molecules and the way heating affects molecular motion, what would happen to the volume of water in the cylinder when it is heated?

• As molecular motion decreases, the space between molecules also decreases.

• Liquid molecules decrease when heating resulting to increase in volume.

• The molecules in hot water move closer together, accounting for the increased volume.

• The molecules in hot water move slightly further apart, accounting for the increased volume.

Which of these statements is true on solid particles?

• Solid particles are moving rapidly.

• Solid particles fly off in any direction.

• Solid particles are tightly packed together.

• Solid particles can slide past with one another.

Which of the following refers to the total amount of space occupied by a body of matter?

• Density

• Mass

• Temperature

• Volume

Why does heat not considered a matter?

• It has volume.

• It occupies space

• Do not have mass.

• It has definite shape.

Why do liquids have the ability to evaporate?

• Liquid particles can slide past one another.

• Liquid particles are relatively close together.

• There are no attractive forces between liquid particles.

• Liquid particles have enough energy to escape into gas state

What is your opinion why soap bubbles are spherical?

• Water spreads out when hydrogen bonds are disturbed making surface tension.

• Soaps and detergents molecules attract each other make greater surface tension.

• Drops of water are spheres in shape, surface area of spheres are smaller than any other shape of same volume.

• Soaps and detergents increase the surface tension of water by disrupting the hydrogen bonds between molecules.

What would happen to the atoms and molecules of a substance when temperature is increased?

• The atoms and molecules stay the same.

• The atoms and molecules will gain energy.

• The atoms and molecules will lose energy.

• The atoms and molecules will collide one another.