Unit 2 Test Review

Cutting a piece of paper in half describes a __________ while burning paper describes a __________.

• physical change; chemical change

• chemical change; physical change

• physical change; physical change

• chemical change; chemical change

Tags

NGSS.MS-PS1-4

In science class, students are conducting an experiment in which they combine an odorless blue liquid at room temperature and an odorless yellow liquid at room temperature. What would be an indicator that a chemical reaction took place?

• The volume of the combined liquids increased.

• The color of the combined chemicals was green

• The combined chemicals smelled like rotten eggs

• The combined chemicals produced a liquid.

Tags

NGSS.MS-PS1-2

Which of the following observations indicate that a chemical reaction has taken place? Select TWO correct answers.

• liquid water evaporating as a result of thermal energy from the sun

• two solutions being mixed together and a solid is formed

• condensation on the window of a house on a cold day

• a sugar cube dissolving after it has been dropped in a glass of water

• gas bubbles forming as a cake is baking in the oven

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student has a balloon with a small amount of baking soda in it. They fit the open end of the balloon over a graduated cylinder containing some vinegar. As they lift the end of the balloon, the baking soda pours into the vinegar causing bubbling and fizzing to occur. The student observes the balloon begin to "fill" up and the graduated cylinder is cold to the touch. Based on these observations, what can they determine about the new substance formed by mixing baking soda with vinegar? Select TWO correct answers.

• The color changed.

• An odor was produced.

• The temperature changed.

• A light was produced.

• A gas was produced.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Which of the following are evidence that a chemical reaction has occurred? Select TWO correct answers.

• salt dissolving in water

• food being chewed into smaller pieces

• bubbles forming

• a solid forming after two liquids are combined

• water evaporating from a beaker

Tags

NGSS.MS-PS1-2

A solid produced by a chemical reaction in solution that separates from the solution is called

• a precipitate

• a reactant

• a molecule

• a solution

Tags

NGSS.MS-PS1-2

Ahmad is participating in stations where he has to determine whether or not the change he is seeing is a chemical or a physical change. At this station, he notices a flask full of a liquid and some blue powder covered by a balloon placed on the lab table. He sees that the balloon is inflating, the liquid is turning the blue color of the powder, and that the flask is getting hotter. How does Ahmad know that he is seeing a chemical change?

• The temperature change proves the chemical reaction since the flask was on a hotplate.

• The temperature change proves what he is seeing is a chemical reaction because there is no source of heat connected to the flask.

• The color change proves that he is seeing a chemical reaction since the liquid was not blue to begin with.

• The color change proves that it was a chemical reaction because the liquid is turning the same color as the powder.

Tags

NGSS.MS-PS1-2

Which of the following is an example of a new substance being formed by a chemical reaction?

• milk souring

• water evaporating

• iron bending

• helium-filled balloon floating

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

According to the chart, which element is most essential to our planet?

• Silicon

• Oxygen

• Nitrogen

• Hydrogen

Tags

NGSS.MS-PS1-1

Which statement below supports why Oxygen is the most essential element?

• The most essential element on Earth is in the atmosphere because all living things need air to survive.

• The most essential element is in the Earth's crust because it is found in decomposed plants and animals.

• The most essential element can be found only in water because all living things need water to survive.

• The most essential element on Earth is plentiful in the ground, living things, and air to sustain life on Earth.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3