Lesson 3: Changes In Matter

One of the ingredients for her main course undergoes physical changes. Which of the following is a physical change?

• cooking eggs

• grilling hamburger

• baking bread

• boiling water

Answer explanation

Boiling water is a physical change as it involves a change in state from liquid to gas without altering the chemical composition. In contrast, cooking eggs, grilling hamburgers, and baking bread involve chemical changes.

For dessert, she prepares to bake a delicious apple pie. During one of the steps, she notices an example of a chemical change. Which one is it?

• softening butter

• folding a sheet of aluminum foil

• heating sugar to make caramel

• dicing an apple

Answer explanation

Heating sugar to make caramel is a chemical change because it involves a transformation of sugar into a new substance through a chemical reaction, while the other options are physical changes.

Tags

NGSS.MS-PS1-2

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As her family eats the delicious dinner, Jia remembers an important fact about the law of conservation of mass. What does she remember?

• Matter always moves from hot to cold.

• Matter is not created or destroyed in any change.

• Matter can change physically or chemically.

• Matter is the amount of mass in a given volume.

Answer explanation

Jia remembers that according to the law of conservation of mass, matter is not created or destroyed in any change. This principle explains that the total mass remains constant during physical and chemical changes.

Tags

NGSS.MS-PS1-5

Anna looks around the ice skating rink and notices many examples of the movement of thermal energy. For example, she sees her friend holding a cup of hot chocolate in the cold rink. Thermal energy flows from _______________ matter to _______________ matter.

Answer explanation

Thermal energy flows from hot matter, like the cup of hot chocolate, to cold matter, such as the surrounding air in the rink. Therefore, the correct completion is 'hot' to 'cold'.

Tags

NGSS.MS-PS3-4

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Gwen is training for a marathon and fueling her body with healthy food. What kind of energy changes the food into energy for her muscles?

• thermal

• solar

• physical

• chemical

Answer explanation

The food Gwen consumes undergoes chemical changes during digestion, breaking down nutrients into energy that fuels her muscles. Thus, the correct answer is chemical energy.

Tags

NGSS.MS-LS1-6

Patrick is giving a presentation on thermal energy to his class. How can he use the terms endothermic and exothermic to explain the change in thermal energy from one substance to another? Give an example of each term.

Answer explanation

Endothermic processes absorb thermal energy, like ice melting. Exothermic processes release thermal energy, such as combustion. These terms help explain how energy transfers between substances during physical and chemical changes.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

The process where a matter alters the form or appearance of a material but does not make the material into another substance is what?

• Physical Change

• Chemical Change

• Climate Change

• New Substance

Answer explanation

A physical change occurs when a material changes its form or appearance without becoming a different substance. Examples include melting, freezing, and dissolving, which all retain the original material's chemical identity.

When one or more substances combine or break apart to form a new substance or substances, what is this process called?

• Climate Change

• Chemical Change

• Physical Change

• Positive Change

Answer explanation

The process of substances combining or breaking apart to form new substances is called a Chemical Change. This distinguishes it from Physical Change, which does not alter the chemical composition.

Tags

NGSS.MS-PS1-2

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What does it mean when nothing is lost or gained; to remain constant?

• conservative

• consummation

• conservation

• consideration

Answer explanation

The term 'conservation' refers to the principle of maintaining a constant state, where nothing is lost or gained. This aligns with the idea of remaining constant, making 'conservation' the correct choice.

Tags

NGSS.MS-PS1-5

Melting butter

• Physical

• Chemical

Answer explanation

Melting butter is a physical change because it alters the state from solid to liquid without changing its chemical composition.

Tags

NGSS.MS-PS1-4