Unit 3 Review

The diagram shows a chemical reaction. Which of the following most likely describes the reaction in the diagram?

• The heat created a chemical reaction between the Magnesium and sulfur, creating a compound of Magnesium Sulfide with new chemical properties.

• The heat created a physical reaction between the magnesium and sulfur, creating a mixture with new physical properties.

• The heat evaporated the magnesium and sulfur, creating a precipitate with new chemical properties.

• The heat melted the magnesium and sulfur, creating a solution with new physical properties.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS1-5

Which of the following scenarios represents a chemical change?

• water changing from a liquid to a gas

• sugar being stirred in a glass of water

• bacteria converting lactose into simple sugars

• food breaking down into smaller pieces through chewing

Tags

NGSS.MS-PS1-2

A student is examining the liquid mercury inside a thermometer. If the liquid is composed of only mercury atoms, what can the student conclude?

• The liquid is a pure substance, represented by the symbol Hg.

• The liquid is a pure substance, represented by the symbol Mg.

• The liquid is an impure substance because it is in a liquid state.

• The liquid is an impure substance because it is inside a thermometer.

Tags

NGSS.MS-PS1-1

Which list correctly matched the elements with their symbols?

• Oxygen O, Silicon Si, Carbon C

• Boron B, Silicon Si, Carbon Ca

• Calcium Ca, Neon Ne, Silicon S

• Magnesium Mg, Neon Ne, Sodium S

A chemical formula is displayed below: (NH₄)₃SO₄. How many atoms, in total, are in this chemical formula?

• 18

• 12

• 22

• 20

Tags

NGSS.MS-PS1-1

A chemical formula is displayed below: 2HNO₃. How many atoms, in total, are in this chemical formula?

• 12

• 18

• 10

• 8

Tags

NGSS.MS-PS1-1

The compound NaCl will dissolve easily in water. The process of dissolving -

• does not cause any change

• increases the pH of the water

• is a physical change

• is a chemical change

What does it mean for a solution to become supersaturated?

• This is when a solvent has no solute in it.

• This is when a solvent has dissolved a solute, but the limit of how much can be dissolved has not been reached yet.

• This is when a solvent has more solute dissolved in it than under normal conditions.

• This is when a solvent has the maximum amount of solute dissolved in it.

Which of the following is a characteristic of a physical change?

• It results in a new substance with different properties.

• It involves a change in the state of matter.

• It involves a change in the atomic structure of a substance.

• It cannot be reversed.

Tags

NGSS.MS-PS1-4

A chemical formula is displayed below: H₂O₂. How many atoms, in total, are in this chemical formula?

• 4

• 6

• 2

• 8

Tags

NGSS.MS-PS1-1