Elements Compounds and Mixtures Quiz 2024

Which of the following is not a compound?

• HCl

• Cl₂

• NaCl

• CO2

Answer explanation

Cl2 is a diatomic molecule consisting of two chlorine atoms, making it an element, not a compound. Compounds are formed from two or more different elements, like HCl, NaCl, and CO2.

Tags

NGSS.MS-PS1-1

Classify the picture with the correct label.

• Mixture of elements

• Mixture of elements & compounds

• Mixture of compounds

• Pure substance, containing compounds

Answer explanation

The correct label 'Mixture of elements & compounds' indicates that the picture contains both individual elements and combinations of those elements in the form of compounds, distinguishing it from pure substances.

Which of the following is an example of of a container filled with a pure substance rather than with a mixture?

• A tire filled with air.

• A jar filled with salt water.

• A balloon filled with helium.

• A glass filled with chocolate milk.

Answer explanation

A balloon filled with helium is a pure substance because helium is a single element, while the other options contain mixtures of different substances (air, salt water, chocolate milk).

The image below is an example of

• an atom

• a molecule

• a homogeneous mixture

• a heterogeneous mixture

Answer explanation

A homogeneous mixture has a uniform composition throughout, meaning its components are evenly distributed. The image likely depicts such a mixture, where the individual substances are not distinguishable from one another.

Tags

NGSS.MS-PS1-2

The image below is an example of

• a homogeneous mixture

• a compound

• a heterogeneous mixture

• an element

Answer explanation

The image represents a heterogeneous mixture because it contains visibly different components that are not uniformly distributed, unlike a homogeneous mixture where the composition is consistent throughout.

A mixture that appears to be evenly mixed throughout:

• an atom

• a compound

• a homogeneous mixture

• a heterogeneous mixture

Answer explanation

A homogeneous mixture is one that has a uniform composition throughout, meaning its components are evenly distributed. This distinguishes it from a heterogeneous mixture, where the components are not uniformly mixed.

diagram "b" is an example of:

• a pure substance containing elements.

• a pure substance containing compounds.

• a mixture containing elements.

• a mixture containing compounds.

Answer explanation

Diagram 'b' represents a pure substance made up of elements, as it does not contain any mixtures or compounds. Pure substances consist of only one type of particle, which in this case are elements.

Tags

NGSS.MS-PS1-1

Which of these is an element?

• Salt (NaCl)

• Water (H20)

• Oxygen (O)

• Carbon Dioxide (CO2)

Answer explanation

Oxygen (O) is an element, which is a pure substance consisting of only one type of atom. In contrast, Salt (NaCl), Water (H2O), and Carbon Dioxide (CO2) are compounds made of two or more elements.

Tags

NGSS.HS-PS1-1

Identifying the category of matter pictured:

• A pure substance containing elements.

• A pure substance containing compounds.

• Homogeneous mixture containing elements.

• Heterogeneous Mixture containing elements.

Answer explanation

The correct choice is 'Heterogeneous Mixture containing elements' because it describes a mixture where the components are not uniformly distributed, allowing for the identification of different elements within the mixture.

Tags

NGSS.MS-PS1-1

Identify what category of matter trail mix would be classified as:

• Element

• Compound

• Homogeneous Mixture

• Heterogeneous Mixture

Answer explanation

Trail mix is a combination of different ingredients like nuts, fruits, and chocolate, which are not uniformly distributed. This makes it a heterogeneous mixture, as the individual components can be seen and separated.