Third Quarterly Examination in Science 8

How will you explain the arrangement of particles in the three states of matter?

• I only

• I and II

• I, II, III

• I, III, IV

Why do particles of solid move in a fixed position?

• They are arranged close to each other.

• They are arranged far from each other.

• They are arranged closely to each other.

• They are arranged very far from each other.

In one of the science activities involving the speed of sound, Juan and his group concluded that sound travels fastest in solids as compared to liquids and gases. Imagine that you are a part of Juan's group. How will you explain your conclusion?

• Sound travels fastest in solids because they exhibit compressibility, malleability, and ductility.

• Sound travels fastest in solids because they have a definite volume, unlike gases which take the volume of their containers.

• Sound travels fastest in solids because their particles are very close together, allowing a more efficient transfer of sound energy between particles.

• Sound travels fastest in solids because there are lesser solid particles of matter as compared to the greater number of gaseous and liquid particles of matter on earth.

A glass of saltwater solution was placed on a windowsill. After a few days, the water has disappeared and there is only a film of white crystals left on the bottom of the glass. Which BEST explains what has happened?

• The salt caused the water to dry.

• The water evaporated and left the salt behind.

• The water condensed and left the salt behind.

• The water and salt evaporated and left the film behind.

Mia accidentally left her sets of pastel colors inside their car during summer. Which of the following explains what happened to her crayons afterward?

• The crayons froze and changed state from liquid to solid

• The crayons melted and changed state from solid to liquid

• The crayon condensed and changed state from gas to liquid.

• The crayons evaporated and changed state from gas to solid

Phase changes is a physical process in which one substance changes phase from one form to another. Which of the following explains what happens to the molecules during a phase change?

• The particles gain energy due to increased temperature.

• The particles gain energy due to decreased temperature.

• The particles lose energy due to increased temperature.

• The particles lose energy due to decreased temperature.

Your mother asked you to boil water. You observed that as water is heated, its temperature rises. Water molecules gain more kinetic energy, and they move faster. Which of the following explains what the gained energy does to the water molecules?

• It arranges the molecules in order.

• It overcomes the forces of attraction.

• It converts it to other forms of energy.

• It increases the number of water molecules.

As one of your summer activities, you and your friends went hiking and you noticed your shirt getting wet from all the sweat. After taking a rest for some time, you feel your shirt becoming dry again. Which of the following phase changes explains your observation?

• Condensation

• Evaporation

• Precipitation

• Sublimation

Your younger brother asked you to explain what happens to the particles of the water as it is being placed in the freezer. How would you explain it to him?

• The particles move faster and farther apart to become ice.

• The particles move slower and farther apart to become ice.

• The particles move faster and closer together to become ice.

• The particles move slower and closer together to become ice.

Upon waking up, you noticed some dew or water droplet on your window glass. Which of the following explains your observation?

• The water vapor condenses into liquid on the glass.

• The hot air meets the cold glass resulting in the transfer of energy.

• The loss of heat from surrounding air causes water vapor on the glass to lose energy.

• The loss of heat from surrounding air causes water vapor on the glass to gain energy.