Chemistry Unit Review

A scientist placed a sample of lithium into a container of water. The scientist observed the lithium floating and making a buzzing sound as gas bubbles were forming around it. Which conclusion is BEST supported by this observation?

• A chemical change took place.

• The lithium was dissolved by the water.

• Dissolved gases were released.

• Water was vaporized.

Tags

NGSS.MS-PS1-2

How many atoms are in one formula unit of magnesium hydroxide, Mg(OH)2

• 6

• 5

• 3

• 4

Tags

NGSS.MS-PS1-1

Where are the most reactive metals located on the periodic table?

• the uppermost complete row of the table

• the rows at the bottom of the table connecting two section

• the column at the far left side of the table

• the second column from the right side of the table

Where are the most reactive nonmetals located on the periodic table?

• the uppermost complete row of the table

• the rows at the bottom of the table connecting two sections

• the column at the far left side of the table

• the second column from the right side of the table

What physical property is characteristic of all of the elements in the group located in the rightmost column of the periodic table?

• very high melting point

• gas state at room temperature

• good conductor of electric current

• extremely brittle solid at room temperature

How does the concept of conservation of mass apply to chemical reactions

• The reactants and products have exactly the same atoms.

• The reactants and products have exactly the same molecules.

• The change in the amount of matter is equal to the change in energy.

• The change in the amount of matter is only a small percentage of the total mass.

Tags

NGSS.MS-PS1-5

Which set of coefficients will balance this chemical equation? _PbS(s) + __O2(g) → 2PbO(s) + 2SO2(g)

• 1,2

• 1,3

• 2,2

• 2,3

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Elements in the periodic table of the elements are organized into columns and rows. The columns are organized to show the

• similarities of the reactivity in groups.

• number of neutrons in a column

• sum of atomic weights per column

• amount of radioactivity in each group

When oxygen combines with hydrogen, which substance is formed?

• water

• vinegar

• hydrochloric acid

• hydrogen dioxide

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

NGSS.MS-PS1-1

Which is the correct way to balance the chemical equation shown below?

Al + O2 → Al2O3

• 2Al + O2 → Al2O3

• 2Al + 3O2 → Al2O3

• 4Al + 3O2 → Al2O3

• 4Al + 3O2 → 2Al2O3

Tags

NGSS.MS-PS1-5