Unit 1 Elements and Compounds Review

Select all of the substances that are elements.

• Baking Soda

  NaHCO3

• Copper

  Cu

• Magnesium

  Mg

• Sugar

  C12H22O11

• Zinc

  Zn

Answer explanation

Copper, Magnesium, and Zinc are all just 1 element.

The rest are compounds because they have more than 1 element.

Which substances are compounds?

• Copper, Sugar, and Water

• Iron, Magnesium, and Zinc

• Water, Nitrogen, Baking Soda

• Baking Soda, Sugar, Water

Answer explanation

Baking Soda is a compound because it's chemical formula is NaHCO3

Water is a compound because it's chemical formula is H2O

Sugar is a compound because it's chemical formula is C12H22O11.

Each one are made of different elements.

Tags

NGSS.MS-PS1-1

Which of the following is the chemical formula for salt

• NaCl

• nacl

• NACL

• clan

Mercury is an element, with the atomic number 80. Which of the following is true?

• Mercury is a pure substance, represented by the symbol Hg

• Mercury is an impure substance because it's a liquid

• Mercury is an impure substance because its a planet

• Mercury is a pure substance, represented by the symbol Mg

Answer explanation

Mercury is a liquid inside a thermometer. It is an element therefore it is a pure substance with the symbol Hg.

Elements are a...

• pure substance made of atoms

• impure substance made of atoms

• water, earth, fire, and air

• pure substance made of compounds

Tags

NGSS.MS-PS1-1

Which of the following is a compound?

• Ag

• Pb

• H2

• NaF

Answer explanation

NaF is the only one with 2 different elements

Na and F

Which of the following is the correct chemical formula for water

• h2o

• h2O

• H2O

• OH

Tags

NGSS.MS-PS1-1

NaCl is the formula for table salt, it is used to season food. What is table salt?

• A compound

• An element

• A mixture

• A solution

Answer explanation

NaCl is a compound with the elements Na and Cl

HCl is one of the substances found in gastric acid, which helps break down food in the stomach. What is HCl?

• A Compound of hydrogen and chlorine atoms

• A Mixture of hydrogen and chlorine atoms

• An element of hydrogen and chlorine atoms

• An impure substance

Answer explanation

HCl is a compound

H=Hydrogen

Cl=Chlorine

Tags

NGSS.MS-PS1-1

The chemical formula for sugar is C12H22O11, so it is a

• Solution

• Mixture

• Element

• Compound

Answer explanation

Sugar is a compound because it has 3 different elements.

C, Carbon

H, Hydrogen

O, Oxygen

Tags

NGSS.MS-PS1-1