C10L1 - Understanding Chemical Reactions

Each substance written to the LEFT of the arrow in a chemical equation is a ____.

• reactant

• product

• precipitate

• catalyst

Tags

NGSS.MS-PS1-5

Which of the following is certain proof a chemical reaction has occurred?

• bubbles

• examining the properties of the matter

• color

• all of these

Tags

NGSS.MS-PS1-2

A change in _____ is a sign of ENERGY being used in a chemical reaction.

• temperature

• odor

• color

• texture

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Which of the following is a result of a chemical reaction?

• water freezing into ice

• painting a fence

• chlorine and sodium forming salt

• ripping a piece of paper

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

All substances _____.

• are elements

• are compounds

• have a fixed composition

• contain hydrogen

If the arrangement of atoms in a substance changes, then which of the following is true?

• A chemical reaction has occurred.

• The physical state of the substance changes.

• The chemical properties of the substance stay the same but the physical properties change.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What has happened to the hydrogen peroxide in the model?

• The bonds in the hydrogen peroxide molecules have disappeared, and it turns into salt.

• The hydrogen peroxide spreads out, and hydrogen peroxide is turned to water vapor and solid oxygen.

• The bonds in the hydrogen peroxide molecules have broken, and it turns into water and oxygen.

• There is no change occurring in the model.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Some baking soda and vinegar were mixed in a closed bag. A students observations of the closed bag are as follows:

Which of the following indicates a CHEMICAL change?

• The bag inflated, indicating a gas has formed.

• The color of the reactants and products stayed the same.

• There is liquid in the bag both before and after.

• The bag is now slightly colder to the touch, indicating a temperature decrease.

Tags

NGSS.MS-PS1-2

2H₂O_{2 --->} 2H₂O + O₂

_{What are the reactants of this equation?}

• hydrogen peroxide (2H₂O₂₎

• water (2H₂O)

• oxygen (O₂₎

• all of these

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

2H₂O_{2 -->} 2H₂O + O₂

_{What are the products of this equation?}

• water (2H₂O) and oxygen (O₂₎

• hydrogen peroxide (2H₂O₂₎

• none of these

• both of these

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5