Matter Unit Test CASC 22-23

A group of chemistry students had to identify six white powders. The students used a variety of tests to identify the powders. They computed the density of each powder. They checked to see if any dissolved in water. One of the powders did not dissolve in water and they thought it was cornstarch. Someone knew that cornstarch felt slippery and reacted with iodine. The students put a few drops of iodine on each white powder. One powder turned black; they guessed that it was cornstarch. They heated the powders in a Bunsen burner flame to see if any would melt. One did and they guessed it might be a sugar.

Which test result indicated a chemical change had taken place?

• dissolves in water

• feels slippery in water

• melts when heated in a flame

• turns black when iodine is added

Tags

NGSS.MS-PS1-2

How many protons would the element with the atomic number 10 contain?

• 8

• 3

• 5

• 10

The table lists the chemical formulas or symbols of a few common substances.

Which two substances are compounds?

• aluminum and iron

• iron and sodium chloride

• carbon dioxide and aluminum

• sodium chloride and carbon dioxide

The red arrow is pointed at different locations of an atom of nitrogen.

Where is it pointing to the GREATEST concentration of atomic mass?

• A

• B

• C

• D

Which TWO locations are MOST probable for locating the cloud of electrons?

• A and B

• B and C

• D and A

• C and D

Electrons are modeled using a "cloud" around the nucleus because they

• move in an orbit about the nucleus.

• exist in many places at once.

• can not be precisely located.

• travel at the speed of light.

Which is an example of an element?

• salt (NaCl)

• water (H20)

• silver (Ag)

• electron (e-)

Which of these is common to ALL chemical changes?

• A new substance is produced.

• A change of color occurs.

• Heat is released into the air.

• A change of state occurs.

Compare the mass of an ice cube to the mass of the water once the cube is completely melted.

• The mass of water formed is more than the mass of ice.

• The mass of water formed equals the mass of ice.

• The mass of water formed does not depend on the mass of ice.

• The mass of water formed is less than the mass of ice.

Which picture represents a molecule?

• A

• B and C

• A and C

• B

Tags

NGSS.MS-PS1-1