Elements, Compounds and Chemical Changes Review

Which of the following is not evidence of a new substance?

• temperature change

• liquid disappears when poured into another

• gas production

• solid formation

Which of the following substances are elements?

• water

• salt

• carbon dioxide

• hydrogen

How many elements are in this Carbon dioxide molecule?

• 3

• 2

• 1

• 0

Tags

NGSS.MS-PS1-1

How many elements are in this potassium chloride (KClO₃) molecule?

• 3

• 4

• 5

• 6

What is true of both elements and compounds?

• They are always made of more than one element.

• They are large.

• They don't last long.

• They are considered to be pure substances.This is a correct answer

If a solid is added to water and then a gas is given off, it is evidence of

• chemical change occurring

• a new product forming

• atoms rearranging

• all are true

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Evaporating, dissolving, & melting are all examples of

• elements

• compounds

• physical changes

• chemical reactions

What is the chemical symbol of magnesium?

• 12

• Mg

• Magnesium

• 24.31

Compounds are different than elements. Compounds are made of

• the same type of element.

• different types of elements.

Tags

NGSS.MS-PS1-1

Which of the following shows evidence of a chemical reaction/change?

• Water being boiled and giving off STEAM.

• Sugar DISSOLVING into a liquid.

• Two liquids are mixed, and a solid FORMS.

Tags

NGSS.MS-PS1-2