P.1.3

When frozen carbon dioxide (CO₂) is heated, it changes directly into a gas. Which statement BEST indicates that a physical change has taken place?

• Heat caused an increase in gas production.

• Heat caused a new substance to form.

• Heat caused a decrease in energy.

• Heat caused a change in state.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

During photosynthesis, carbon dioxide and water combine according to the general equation. Why is photosynthesis a chemical reaction?

• because new substances are formed

• because an input of energy is required

• because the reactants are compounds

• because the products include an element

Tags

NGSS.MS-LS1-6

Which is the BEST explanation of why heat is released when wood burns?

• Burning creates energy by increasing particle motion.

• Burning destroys matter and creates energy from it.

• Burning releases energy stored in chemical bonds.

• Burning causes convection currents which create heat energy.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which statement BEST describes the change to an ice cube as it melts?

• The change is physical because the mass remains the same.

• The change is physical because the substance remains the same.

• The change is chemical because water has a different pH than ice.

• The change is chemical because ice has a lower density than water.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Which statement BEST describes the formation of rust?

• Rust results from a physical mixing of iron with water.

• Rust forms from a chemical breakdown of old metal.

• Rust results from a chemical reaction between iron and water.

• Rust forms from a physical change when wind blows against metal.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

As part of a study, a scientist observed a number of different molecular changes in matter. Which of the following observations provides evidence of a physical change?

• using heat to burn a log in a fireplace

• using light to produce sugar in plants

• a cake that was baked from many ingredients

• a bottle that was broken into many small pieces

A science class is studying the states of matter. One group of students freezes 100 grams (g) of water in a cup. Another group of students melts 50 g of ice in a cup. Which of these will MOST likely occur at the end of the experiment?

• The temperature of both cups will be the same.

• Both samples in the cups will be in the same state.

• Both groups will have the same mass with which they started.

• The time required for the changes in states of matter will be the same.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Which task in the kitchen is an example of a physical change?

• frying an egg

• baking a cake

• toasting bread

• melting butter

John and Lisa collected a sample of ocean water and placed it in a jar. Within a couple of days, the water had evaporated and salt was visible at the bottom of the jar. This is an example of a

• chemical change

• physical change

• solute being dissolved

• new substance being formed

Tags

NGSS.MS-PS3-4

What is needed to change ice into water?

• air

• energy

• stirring

• chemicals

Tags

NGSS.MS-PS1-4