Science 7th Grade Week 3

Students at a bonfire noticed that a large amount of gas and ash were produced as they watched the logs of wood burn. Which statement best explains the type of change that occurred as the logs of wood burned?

• A physical change occurred because the ash and gas produced can easily be turned back into wood.

• A chemical change occurred because the atoms in the wood reacted with oxygen and rearranged to form new combinations of atoms and molecules.

• A physical change occurred because the atoms in the wood changed from a solid state to a gaseous state as the atoms in the wood burned.

• A chemical change occurred because a chemical reaction occurs any time heat is added to a substance.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Students conducted an experiment in which sugar was added to separate beakers of water and sulfuric add. Once the sugar was added, the students recorded their observations:

Beaker #1 (sugar and water): no color change, no solid forms, solid sugar dissolves, no bubbles

Beaker #2 (sugar and sulfuric acid): color change, solid forms, bubbles form, gas given off

• Beaker #1

• Beaker #2

• both Beaker #1 and Beaker #2

• neither Beaker #1 nor Beaker #2

Tags

NGSS.MS-PS1-2

If all objects' volumes are the same, then the object with the most ______ is the densest.

• volume

• density

• mass

• Area

A chemical change occurs when...

• the identity of a substance changes but its appearance does not.

• neither the appearance of a substance nor its identity changes.

• both the physical properties of a substance and its identity change

• the appearance of a substance changes but its identity does not.

Tags

NGSS.MS-PS1-2

What atoms combine to make up a molecule of water?

• 1 hydrogen, 1 oxygen

• 1 hydrogen, 2 oxygen

• 2 hydrogen, 1 oxygen

• 2 hydrogen, 2 oxygen

Tags

NGSS.MS-PS1-1

The atomic mass is equal to which two items listed below?

• protons

• neutrons

• electrons

• atoms

As thermal energy is added to a substance, which of the following changes can be predicted?

• Spacing between particles will decrease.

• Vibration of the individual particles will increase.

• Temperature of the substance will decrease.

• The pressure of the substance will increase.

Tags

NGSS.MS-PS1-4

Select all of the following events in which a chemical change occurs.

• Chocolate syrup dissolves into warm milk.

• Toast is lightly charred in a toaster.

• A piece of paper is cut up into 12 pieces.

• Two unknown liquids are mixed together and a gas is produced.

• Sugar is heated until it turns into a brown caramel sauce.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of these is NOT a physical property of matter? Select All that apply.

• density

• flammability

• hardness

• luster

• reactivity

Forces have both

• distance

• direction

• strength

• mass

Tags

NGSS.MS-PS2-2