Elements, Compounds, Mixtures

A mixture that appears to be evenly mixed throughout:

• an atom
• a compound
• a homogeneous mixture
• a heterogeneous mixture

A substance made up of two or more chemically combined elements is

• an element

• mixture

• compound

• solution

Two or more physically combined substances form —

• a compoud
• an acid
• an element
• a mixture

Tags

NGSS.MS-PS1-1

A substance that cannot be broken down into any other substance by ordinary chemical means is called

• molecule

• mixture

• element

• compound

NaHCO₃ is an example of —

• an abbreviation
• a compound
• a mixture
• an element

Tags

NGSS.MS-PS1-1

A substance made of only one type of atom is called —

• an element
• a mixture
• a compound
• a salt

Tags

NGSS.MS-PS1-1

What is an example of an element?

• Oxygen
• Pure water
• Air
• Table salt

Two or more substances in the same place but NOT chemically combined is a

• a compound

• a pure substance

• an element

• a mixture

Which of the following is an example of the formation of a mixture?

• Rust forming on an iron nail.

• Sugar crystals dissolving in water.

• Sodium and chlorine forming table salt.

• Hydrogen and oxygen reacting to produce oxygen.

Which statement identifies why oxygen is classified as a pure substance and air is classified as a mixture?

• Oxygen is more reactive than air.

• Oxygen has a higher density than air.

• Oxygen goes under a phase change, whereas air is always a gas.

• Oxygen contains only one substance, but air contains several substances.