Pure Substances, Mixtures, and Chemical Bonds Questions

From the list below, determine which properties are for compounds.

• I & II

• II & III

• I, II & IV

• II, III, & IV

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

While elements and compounds can both be classified as pure substances because they have distinct properties and composition, __________ cannot be decomposed further.

• compounds

• elements

• formulas

• molecules

24-karat gold is considered to be pure gold. 18-karat gold is considered to be about 75% gold. What is 18-karat gold considered a mixture rather than a pure substance?

• It has a variable composition of other elements and minerals.

• Its color is different than pure gold.

• The gold atoms are not arranged in a repeating pattern.

• It can be melted and transformed into a different substance.

Elements are pure substances that make up all matter. Gold, aluminum, iron, and lead are some examples of these pure substances. What is the basic building block of all pure substances that make up matter in the world?

• atoms

• cells

• compounds

• metals

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

Jim collects a sample of beach sand during a class trip. After a close inspection of the sample he classifies it as a ____________ mixture.

• heterogeneous

• heterologous

• homogeneous

• homologous

Tags

NGSS.MS-PS1-1

Salt, NaCl, is a pure substance, while saltwater is a mixture. What this means is that the ratio of sodium to chloride in salt ____________, and the ratio of salt to water in a saltwater solution _____________.

• is constant; can be altered

• can be altered; is constant

• is constant; is constant too

• can be altered; can be altered too

A mixture is what you get when you combine two substances in such a way that no chemical reaction occurs between the components. A solution is a mixture that looks exactly the same everywhere. Which of these mixtures is not a solution?

• A glass of apple juice.

• A chocolate chip cookie.

• A mixture of salt and water.

• A mixture of sugar and water.

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

NGSS.MS-PS1-5

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.

Which of these is not considered a pure substance?

• An atom

• mixture

• Element

• compound