Classifying Compounds and Atomic Structure

A student is given the following chemical formula: H2O, CO2, and NaCl

Which of these are compounds, and what evidence from the formulas supports your answer?

• H2O and CO2; they contain two or more different elements

• O2 and NaCl; they contain two or more atoms

• H2O and O2; they contain hydrogen and oxygen

• CO2 and O2; they contain carbon and oxygen

Tags

NGSS.MS-PS1-1

A student is studying an atom of carbon. The atom has 6 protons and 6 neutrons.

Which value represents the mass number of this carbon atom, and how is it determined?

• 6; it is the number of protons only

• 12; it is the sum of protons and neutrons

• 6; it is the number of electrons only

• 12; it is the number of protons minus neutrons

Tags

NGSS.MS-PS1-1

A student heats a cup of water until it boils, then removes it from the heat to cool. They observe the water temperature slowly dropping.

Which statement best explains what happens to the energy and motion of the water particles as it cools?

• the energy decreases, and the speed of its particles increases

• the energy decreases, and the speed of its particles decreases

• the energy increases, and the speed of its particles increases

• the energy increases, and the speed of its particles remains the same

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Classify the following as Element, Compound, Mixture

MgCl2

• element

• compound

• mixture

Tags

NGSS.MS-PS1-1

Classify the following as Element, Compound, Mixture

CO2

• element

• compound

• mixture

Tags

NGSS.MS-PS1-1

Classify the following as Element, Compound, Mixture

C + H2

• element

• compound

• mixture

Tags

NGSS.MS-PS1-1

A student places a piece of aluminum in three substances: water, sulfuric acid, and air. They observe aluminum bubbles in sulfuric acid, stays the same in water, and forms a thin layer in air.

Which observation shows a chemical property of aluminum?

• it stays the same in water

• it forms a thin layer

• it stays shiny

• it bubbles in sulfuric acid

Tags

NGSS.MS-PS1-2

A city engineer notices railroad tracks have small gaps on a hot day. Why are these gaps necessary, and what would happen without them?

• the gaps allow heat to escape; without them, rails would rust

• the gaps reduce heat absorption; without them, trains would slow down

• the gaps allow thermal expansion; without them, rails could buckle or bend

• the gaps provide insulation; without them, rails would conduct too much heat

Select the appropriate term to complete each statement:

Part A: As volume increases, __________ decreases

Part B: As volume increases, ___________ increases

• pressure, temperature

• temperature, pressure

Which graph best shows the relationship between volume and temperature of a gas at constant pressure and number of molecules?

• 
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Tags

NGSS.MS-PS1-4