Chemistry

1.     Liz knows that changes can alter the looks or shape of a substance.

Cutting, melting, bending, or crushing are examples of what kind of change?

• reactant

• product

• physical

• chemical

After reading about the kinds of changes that occur, Liz saw some rust on a pipe that was going into her house. What kind of change is the formation of rust?

• reactant

• product

• physical

• chemical

Tags

NGSS.MS-PS1-5

After learning about chemical reactions, Olivia investigated different kinds of chemical changes using substances she found in her kitchen so she could see these changes. Which of the following can occur when a chemical reaction takes place? Choose the three statements that apply.

• New bonds form.

• Existing bonds break.

• Changes don’t affect matter.

• New substances form.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Kim understands that several signs indicate a chemical reaction has occurred. What is the best way to be certain that a chemical reaction has occurred?

• Some bubbles form.

• A color change occurs.

• A new substance forms.

• The materials do not react.

Tags

NGSS.MS-PS1-2

Leandra is learning about chemical reactions and she wants to examine the information that is included in a chemical equation. Which pieces of information does a chemical equation include? Choose the three that apply.

• the kinds of atoms that form during a reaction

• the kinds of molecules involved in the reaction

• the kinds of elements that make up a molecule

• whether the molecules are products or reactants

Tags

NGSS.MS-PS1-1

One day on her walk home from school, Leann noticed some rust on an old car. She remembered that chemical equations can summarize what happens in a chemical reaction. What is the name of the two parts found on the left side of the equation below?

4 Fe + 3O ₂ → 2Fe ₂ O ₃

• products

• reactants

• scientific notation

• synthesis

Tags

NGSS.MS-PS1-1

Keesha performed a chemical reaction, and the products looked quite different from the reactants. She knew the amount of matter had not changed due to the law of conservation of mass. According to the law of conservation of mass, what happens in a chemical reaction?

• Matter is not created or destroyed and the same amount of mass remains.

• A new kind of matter is created and the amount of mass either increases or decreases.

• Matter is not created or destroyed and the amount of mass may change after the reaction.

• New matter is created and changes form so that the mass of the reactants and the products will almost be equal.

Tags

NGSS.MS-PS1-5

James planted seeds in a pot and after a few days, a plant started to grow. It appeared that the plants carrying out photosynthesis had more mass than what was being taken in. Plants are often in a system where the matter going in and out can’t be controlled or observed. What kind of system do most plants function within?

• decomposition system

• manufactured system

• closed system

• open system

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

In a ________________atoms and molecules rearrange to form new ones.

• Chemical reaction

• Physical reaction

• Physical change

• Physical change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Cutting wood is an example of __________

• Physical change

• Chemical change

• All of the above

• None of the above