Elements, Compounds and Mixtures

Potassium iodide can be decomposed by electrolysis (an electric current) into the elements potassium and iodine. Based on this information, how would potassium iodide be classified?

• Compound

• Heterogeneous Mixture

• Homogeneous Mixture

• Solution

Ammonia is made up of two pure substances: nitrogen and hydrogen. What can be true for ammonia, nitrogen, and hydrogen?

• Ammonia is made up of two pure substances: nitrogen and hydrogen. What can be true for ammonia, nitrogen, and hydrogen?

• Ammonia is a mixture, and nitrogen and hydrogen are compounds.

• Ammonia is a compound, and nitrogen and hydrogen are elements.

• Ammonia is an element, and nitrogen and hydrogen are compounds.

Tags

NGSS.MS-PS1-1

When chemical W is added to a liquid, the chemical breaks down into substances X, Y, and Z. It is not possible to break down substances X, Y, and Z into simpler substances. What conclusion is supported by this evidence?

• Chemical W is an element

• Substances X, Y, and Z are elements

• Chemical W is a pure substance

• Substances X, Y and Z are compounds

Tags

NGSS.MS-PS1-1

The human body is composed primarily of water, sugar, protein, and fat. How are each of those individual substances classified?

• Compounds

• Elements

• Heterogeneous Mixtures

• Homogeneous Mixtures

Tags

NGSS.MS-PS1-1

Water, a stable liquid, is formed when two flammable gases, hydrogen and oxygen combine. What has happened?

• An atom has been created.

• A compound has been created.

• A mixture has been created.

• An element has been created.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Adam analyses a sample of a substance. He concludes that it consists of more than one type of atom chemically combined. What does the substance represent?

• an element

• a heterogeneous mixture

• a homogeneous mixture

• a compound

Tags

NGSS.MS-PS1-1

A substance is examined under a high-power electron microscope. The substance is found to contain only one type of atom.

• element

• compound

• mixture

• solution

What composes an element?

• atoms of the same element

• compounds of the same structure

• mixtures of different substances

• molecules of different structures

Tags

NGSS.MS-PS1-1

Which type of matter is an example of an element?

• sugar

• salt

• carbon

• water

Which substance is an element?

• Al

• CO

• HF

• NO₂