8th Grade Chemistry Unit Benchmark Review

Front

What class of solids is made up of regularly, repeating subunits of tightly packed, orderly arrangement of atoms, ions, and molecules?

Back

a crystalline solid

Front

What is nitrogen's state of matter at -215 degrees C? Options: liquid, solid, plasma, gas

Back

solid

Front

Which of the following chemical formulas represents an element, but not a molecule? C, H2O, H2, NH3

Back

C

Front

Which statement below is also true of the rearrangement of atoms? The amount of matter is conserved., The amount of matter decreases., The number of substances increases., The number of substances is conserved.

Back

The amount of matter is conserved.

Front

What does the data show is occurring? Options: The hydrochloric acid and magnesium metal react to form a soluble compound., The hydrochloric acid and magnesium metal do not react., The hydrochloric acid and magnesium metal react to form a precipitate., The hydrochloric acid and magnesium metal react to form a gas.

Back

The hydrochloric acid and magnesium metal react to form a gas.

Front

Which picture correctly represents a group of molecules? Select the correct image.

Back

Front

Which of the following statements best describes the Law Of Conservation of Mass? Atoms are created by some reactions and destroyed by others., Energy is created as atoms and destroyed in chemical reactions., Every atom destroyed in a chemical reaction must be replaced., Atoms cannot be created or destroyed by chemical reactions.

Back

Atoms cannot be created or destroyed by chemical reactions.

Front

An orange is left on the kitchen counter. Which of the following would I do if I wanted to slow down/ decrease the movement/speed of the particles? Options: Put the orange in the window on a sunny day, Put the orange in the microwave or the oven., Eat for dinner., Put the orange in the freezer.

Back

Put the orange in the freezer.

Front

June is building a model of a water molecule with balls and sticks. Which of these is the best model for her to build? (Hint: A molecule is two or more atoms bonded together. A water molecule (H2O) is two hydrogen atoms and an oxygen atom bonded together.)

Back

Front

Molecular motion varies between the different states of matter. For example, the molecules in ___________ move more/faster than the molecules in ____________.

Back

gases, solids