Compounds and Chemical Reactions

Evidence of a chemical change does NOT include

• producing a gas.

• change in color.

• change in shape.

• change in temperature.

Tags

NGSS.MS-PS1-2

Which of the following are evidence(s) of a chemical change that you see in the picture? (Select all that are correct.)

• giving off light

• wood

• camping

• temperature change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Production of Gas or Bubbles is evidence of a

• Physical Change

• Chemical Change

Tags

NGSS.MS-PS1-2

How many atoms in a molecule of water? H₂O

• 4

• 3

• 2

• 1

Tags

NGSS.MS-PS1-1

How many elements create chocolate?

• 3

• 22

• 4

• 21

Tags

NGSS.MS-PS1-1

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

• reactant

• product

• precipitate

• catalyst

Tags

NGSS.MS-PS1-2

According to the law of conservation of mass, how does the mass of the products in a chemical reaction compare to the mass of the reactants?

• There is no relationship.

• The mass of products is sometimes greater.

• The mass of reactants is greater.

• The masses are always equal.

Tags

NGSS.MS-PS1-5

A substance that speeds up chemical reactions in the human body is ____.

• an inhibitor

• an enzyme

• polar

• a prohibitor

Tags

NGSS.MS-LS1-7

Which one of the following factors would not speed up a chemical reaction?

• increasing the concentration of a reactant

• adding a catalyst

• raising the temperature

• making the reactant particles larger

Tags

NGSS.HS-PS1-5

In the compound, H2O, the electrons in the bonds are unequally shared between oxygen and hydrogen, forming ____.

• cations

• nonpolar molecules

• ionic bonds

• polar bonds