Science Grade 8 STAAR

Which statement about the sun is true?

• It is the hottest star in the universe

• It is closer to Earth than any other star

• It is located in the centre of the Milky Way galaxy

• It is the largest type of star known to exist.

Which statement BEST describes a component of cell theory?

• All cells form

  from molecules

• All cells come from pre-existing cells

• All cells create genetically identical cells

• All cells reproduce from simpler cells

Students measure and record the mass and volume of a sample of material.

Mass (g) = 35

Volume (cm³) = 14

The table shows the densities for four substances. Based on the density of the sample, which material is the sample MOST LIKELY made of?

• Plywood

• Aluminium

• Rubber

• Glass

Controlled burns are fires that are purposely set within a designated area when conditions are safe for the public and for the firefighters who watch over the fire. Weather and forest conditions are monitored both before and during the burn. Controlled burns rid forests of tree limbs, dead leaves, and other debris.

Which prediction can be made about a forest after a controlled burn has occurred?

• The ability of plants to reproduce will decreases

• Important nutrients for new plant growth will be returned to

  the soil

• Short term air quality in the area will improve

• Long term biodiversity will be reduced

Students are baking a cake. They mix together all the necessary ingredients and pour them into a pan. Then they place the pan into the oven to cook for 40 minutes. Which statement BEST explains why baking a cake is evidence of a chemical reaction?

• The state of matter of some of the ingredients changed while being cooked

• The total mass of the ingredients was the same before and after they were cooked

• The temperature of the ingredients increased as they absorbed thermal energy from the oven

• The ingredients formed a new substance after they were cooked in the oven

Which factor contributes MOST to the formation of a hurricane?

• High water temperatures

• High water

  density

• High water

  oxygen levels

• High water

  volume

A student researches an ecosystem and

draws the food web shown. A student researches an ecosystem and draws the food web shown.

A student graphs the motion of a toy car moving in a straight

line over a 10‑second time period. Which statement BEST

describes the motion of the car?

• The car moved at a speed of 5 meters per second during the first 5 seconds and then moved at a slower speed during the next 5 seconds

• The car moved at a speed of 5 meters per second during the first 5 seconds and then moved at a faster speed during the next 5 seconds

• The car moved at a speed of 1 meter per second during the first 5 seconds and then moved at a slower speed during the next 5 seconds

• The car moved at a speed of 1 meter per second during the first 5 seconds and then moved at a faster speed during the next 5 seconds