S8P1a - Pure Substances & Mixtures

Summarize the Venn diagram.

• Compounds are found inside the matter of atoms.

• A pure substance may contain subatomic particles but not atoms.

• Compounds are the most basic form of matter. They combine to form larger atoms.

• Atoms are the most basic form of matter. They combine to form larger electrically stable compounds.

Tags

NGSS.MS-PS1-1

One difference between mixtures and pure substances is that

• mixtures can be physically separated.

• mixtures are made of one type of atom.

• pure substances have no chemical bonds.

• pure substances can be physically separated.

To make salt water a heterogeneous mixture, you would have to

• add sand.

• add a small amount of sugar.

• boil the water.

• remove the salt.

Taylor was thirsty and decided to mix up a pitcher of lemonade. She put lemon juice, water, and sugar into a pitcher and stirred it to create this wonderful new drink. How could Taylor decide if she just created a mixture or a compound?

• it must be a compound because it all looks the same

• if it were a compound, there would have been an explosion

• it must be a mixture as she can separate all of the individual ingredients

• it must be a compound as she can separate all of the individual ingredients

The table lists the chemical formulas or symbols of a few common substances. Which two substances are compounds?

• aluminum and iron

• iron and sodium chloride

• carbon dioxide and aluminum

• sodium chloride and carbon dioxide

Tags

NGSS.MS-PS1-1

The approximate composition of the atmosphere is shown in the pie-chart. Which statement BEST describes the chart?

• The chart shows the percentages of elements in a mixture.

• The chart shows the percentages of elements in a compound.

• The chart shows the percentages of pure substances in a mixture.

• The chart shows the percentages of compounds in a pure substance.

Imagine you have mixed together some sand and salt. Based on the Venn diagram, this mixture would be placed where?

• A

• B

• C

• D

A student drops some metal paper clips in a box of sand. The student uses a magnet to separate the metal paper clips from the sand. The reason this works is that the sand and paper clips together are _____.

• a mixture

• an element

• a compound

• a substance

Tim puts his spare change in a jar each day when he comes home. When the jar is full he separates the coins and takes them to the bank. The coins would be classified as a _________.

• compound

• element

• mixture

• solution

Air can be considered a mixture. Which statement helps describe air?

• Air contains a fixed ratio of atoms.

• The components of air separate into visible layers.

• The components of air can be separated by chemical means.

• The exact mixture of components varies from point to point.

Tags

NGSS.MS-ESS2-6