Quarter 2 Practice

Pierre is studying the stars, and he learns that Bernard's star is the third closest star to Earth, although it cannot be seen without a telescope. He also knows that the brightest star in the sky, Sirius, can be seen by the naked eye but is much farther away. Which of the following explains why Sirius can be seen without a telescope?

• A. All stars are the same temperature, so Sirius must be larger than Bernard's star.

• B. All stars are the same size, so Sirius must be hotter than Bernard's star.

• C. Sirius is much larger and hotter than Bernard's star.

• D. Bernard's star is much larger and hotter than Sirius.

A student followed these steps for an investigation:

1. Place 2 grams (g) of salt in 500 milliliters (mL) of water at room temperature.

2. Stir the salt and water together until the salt can no longer be seen.

3. Record the amount of time needed for the salt to dissolve completely.

4. Repeat steps 1-3 using hot water.

5. Repeat steps 1-3 using cold water.

What is the student testing in this investigation?

• A. how much salt can be dissolved in water in a given amount of time

• B. how the amount of water affects the time it takes for salt to dissolve

• C. how temperature affects the time it takes for salt to dissolve in water

• D. how much time it takes for different amounts of salt to dissolve in water

Mel is watching a demonstration of glassblowing. An artist heated up sand causing it to melt into glass. Mel noticed that the glass is red-hot after taking it out of the furnace. After the artist blew into the pipe, it expanded and started to cool. As the color faded from the red-hot temperature, Mel noticed that the artist sealed the end of the tube, trapping hot air inside. The artist continued working on the surface of the glass which was still very soft and workable. When the artist finished creating the glass sculpture, she talked with Mel and told him that sand and glass have the same chemical formula.

Which of the following best describes the type of change that the sand experienced in order to be turned into glass?

• A. The sand experienced a chemical change because it became hot when turning into glass.

• B. The sand experienced a chemical change because it turned red when turning into glass.

• C. The sand experienced a physical change because it was able to be manipulated when turning into glass.

• D. The sand underwent a physical change because its chemical structure remained the same when turning into glass.

Diego carefully places ten marbles into a graduated cylinder filled with water, making sure no water splashes out. He then measures how high the water level rises and divides this value by ten. He then repeats this process using ten metal jacks. What property of the marbles and the jacks can Diego now directly compare?

• mass

• shape

• temperature

• volume

All matter is composed of parts too small to be seen without magnification. What is the smallest unit of matter?

• atoms

• compounds

• gases

• molecules

Mark put the same amount of water onto two plates. He placed one plate in direct sunlight and the other in the shade. After a few hours, he observed that most of the water had disappeared from the plate in the sunlight, but only a little had disappeared from the plate in the shade.

Which hypothesis is best supported by the observations from his experiment?

• A. If a plate of water is placed in the sunlight, then it will heat up.

• B. If a plate of water is placed in the shade, then the water cycle does not go forward.

• C. If a plate of water is placed in sunlight, then it will evaporate faster than water placed in the shade.

• D. If a plate of water is placed in the shade, then it will collect more water as long as it stays out of the sunlight.

Blake added 10 grams of salt to 500 milliliters of water to make a weak solution. Which action would increase the speed at which the salt dissolved in water?

• A. Place the solution in the freezer.

• B. Stir the solution with a mixing rod.

• C. Add the salt to the water one grain at a time.

• D. Double the amount of salt added to the water.

Where can the most asteroids be found in our solar system?

• By the sun.

• The asteroid belt in between the inner and outer planets.

• Next to Jupiter.

• Saturn's rings.

A group of students wants to create a model of the water cycle. Which characteristic of the model is most important if they want to observe condensation?

• A. The model should have a tight-fitting lid.

• B. The model should be placed in a dark closet.

• C. The model should have soil to absorb the water.

• D. The model should have space for the new water that is produced.

Mrs. Garcia's class is studying galaxies. She asked a student to describe a galaxy. Which statement is the best description of a galaxy?

• A. gas, dust, billions of stars, and planets

• B. a star, planets that orbit the star, gas, and dust

• C. a planet, moons that orbit the planet, gas and dust

• D. a group of planets, moons that orbit planets gas, and dust