NC Science

Why is water classified as a compound?

• Because it is an element, which consists of only one type of atom.

• Because it is a substance, which can easily be separated.

• Because it is a substance composed of two or more kinds of atoms bonded together.

• Because it is an unevenly mixed solution, or a heterogeneous mixture.

Tags

NGSS.MS-PS1-1

A student is designing an experiment for the science fair.  She needs to find a material that conducts an electric current, and her teacher has provided her with samples of the following elements.  Which of them should she choose?

• argon

• fluorine

• copper

• phosphorous

Tags

NGSS.MS-PS1-1

The mass of the products in a chemical reaction is the same as the mass of the reactants in the reaction. Which law best describes this statement?

• The Law of Conservation of Angular Momentum

• The Law of Superposition

• The Law of Conservation of Matter

• The Law of Entropy

Tags

NGSS.MS-PS1-5

A scientist recognizes a white powder as sugar due to its white crystals and its sweet taste.  However, the scientist notices that the elements that make up the sugar - carbon, hydrogen, and oxygen - look nothing like sugar, nor are they sweet.  What is the best explanation for this?

• Sugar is a compound, and compounds usually have a different appear

• Sugar is an element, so its properties are unique.

• Sugar is a heterogeneous mixture, so its appearance is unique.

• Substances in nature change randomly and it is impossible to predict those changes.

Tags

NGSS.MS-PS1-1

The population density of marine life is denser along the shorelines of the ocean than farther out in the deep waters of the ocean.  Which statement provides the BEST reason for this situation?

• Ocean currents prevent many smaller marine organisms from living in deep water.

• The shallow waters have fewer predators.

• Coastal waters are less polluted than the deeper waters of the ocean.

• There are more nutrients in shallow waters.

Tags

NGSS.MS-LS2-1

How can a scientist, using the periodic table, find an element with properties similar to another element?

• by comparing density

• by finding its periodic group

• by comparing malleability

• by comparing atomic weight

A scientist has a hypothesis that a large volcanic eruption caused a change in global temperature. Which information gained from ice cores is MOST useful in supporting the scientist's hypothesis?

• levels of dissolved oxygen

• identities of trace metals

• estimates of natural radioactivity

• amounts of atmospheric dust

Tags

NGSS.MS-ESS3-5

Which BEST explains the importance of dissolved gases in the ocean?

• They help control pollution.

• They help provide oxygen for aquatic animals.

• They help maintain a constant water temperature.

• They help maintain constant levels of salinity.

After a chemical reaction occurs in an open test tube, measurements indicate that the mass of the reactants is greater than the mass of the products remaining in the test tube.  What MOST LIKELY explains the measurements?

• A gas was produced.

• A solid was produced.

• The salinity of the reactants was high.

• The temperature of the reactants was low.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student is asked to categorize the following items as elements, compounds, or mixtures: copper wire, salt, aluminum foil, baking soda, a piece of granite, and sugar water. He lists ELEMENTS as copper wire, aluminum foil, and baking soda; COMPOUNDS as salt; MIXTURES as the piece of granite. Which is in the wrong category?

• copper wire

• baking soda

• sugar water

• salt