Distinguishing Pure Substances from Mixtures

What is matter primarily composed of?

• Plasma

• Light and heat

• Atoms and molecules

• Energy

Tags

NGSS.MS-PS1-1

What defines an element in chemistry?

• A single type of molecule

• A single type of atom

• A compound of atoms

• A mixture of different atoms

What is a compound?

• A mixture of molecules

• An isolated molecule

• A chemical bond between atoms forming a molecule

• A single type of atom

Tags

NGSS.MS-PS1-1

Which property is not a characteristic of pure substances?

• Uniform boiling point

• Varied density

• Consistent chemical composition

• Specific melting point

What is the main characteristic of a homogeneous mixture?

• Different properties in different parts

• Uniform composition throughout

• Only one type of molecule

• Visible separation of components

How can mixtures be separated?

• By heating only

• By physical methods

• Cannot be separated

• By chemical reactions

What distinguishes a heterogeneous mixture?

• Uniform distribution of components

• Visible layers or phases

• Single type of atom

• Chemical bonding between components

Why is aluminum foil considered a pure substance?

• It contains multiple elements

• It is a compound

• It consists only of aluminum atoms

• It is a mixture

What type of mixture is air classified as?

• Heterogeneous mixture

• Element

• Homogeneous mixture

• Pure compound

What type of mixture is pizza considered to be?

• Homogeneous mixture

• Heterogeneous mixture

• Compound

• Element