7th Grade Benchmark Review

A ______ change occurs when one or more substances change into entirely new substances.

• physical

• chemical

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

____ changes may result in the formation of a precipitate when liquids combine to form a solid.

• physical

• chemical

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

To increase the rate of a chemical reaction, you can ____.

• Put the reactants together faster

• Decrease the temperature

• Increase the temperature

Tags

NGSS.MS-PS1-4

Filling an ice cube tray with water that freezes and forms ice cubes is a _______ change.

• physical

• chemical

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Students performed a lab investigation on chemical reactions. The students put on goggles and plastic gloves and then followed the steps below. Which observation would indicate that a chemical reaction occurred?

• The vinegar took the shape of the container in step 1
• The steel wool sank into the vinegar in step 3
• The temperature of the vinegar increased during step 4
• The steel wool changed shape during step 6

Tags

NGSS.MS-PS1-2

A silver ring reacts with compounds containing sulfur in the air to form silver sulfide, a black substance that makes up the tarnish on the surface of silver objects. To remove the tarnish from the ring students placed it in a pan with aluminum foil and added hot water. Baking soda was added to the hot water and stirred. Students made observations about the process. Which observation of this process provides evidence of a chemical reaction?

• Hot water heated the aluminum foil
• The liquid solution changed color
• The pan was lined with aluminum foil
• The hot water cooled

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

NGSS.MS-PS1-4

4 NaCl represents several molecules of table salt. How many atoms of chlorine are present in this example?

• 1

• 4

• 8

Tags

NGSS.MS-PS1-1

Determine whether the following equation is balanced or unbalanced. 4P +5O_{2 --->} 2P₂O₅

• Balanced

• Unbalanced

Tags

NGSS.MS-PS1-5

In order for an equation to be balanced, there must be ...

• an equal amount of atoms on both sides

• a greater mass on the product side

• a greater mass on the reactant side

• elements with the same atomic # on both sides

Tags

NGSS.MS-PS1-5

What does the Law of Conservation of Mass state?

• Matter cannot be gained or lost in a chemical reaction.
• Matter can only be lost in a chemical reaction.
• Matter can only be gained in a chemical reaction.
• Matter can be gained and lost in a chemical reaction. 

Tags

NGSS.MS-PS1-5