9th grade physical and chemical changes

The three ways contemplated in class to illustrate a process are

• Mathematical, chemical, and abstract

• Chemical, abstract and pictorical

• Pictorical, textual, and shorthand

• Mathematical, analytical, and net

When dry ice (solid carbon dioxide) sublimes it goes directly from a solid to a gas. What type of change is occurring? 

• Chemical change
• Physical change
• None of the above 

Tags

NGSS.MS-PS1-4

What state of matter is this substance in?

• Solid

• Liquid

• Soluble

• Aqueous

Which compound is formed as a precipitate in this reaction?

• Pb(NO₃)₂

• KI

• PbI₂

• KNO₃

Is the compound in the pink box a reactant or a product?

• Reactant

• Product

• Neither

Chemical reactions

• create and destoy atoms

• only occurs outside living organisms

• occurs only in living organisms

• produce new substances

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

NGSS.MS-LS1-7

What does this symbol Δ above the arrow mean?

• A precipitate is formed

• Heat is supplied

• A catalyst is needed

• Electricity is needed

Chemical equations...

• Give directions for naming compounds

• Describe only biological changes

• Describe chemical reactions

• Show how to write formulas

In the chemical equation H₂O₂(ag) → H₂O(l) + O₂(g), the O₂ is a

• Reactant

• Yield

• Product

• Solid

Which of the following is a chemical reaction?

• Sodium and chlorine atoms bond to form salt molecules.

• Ice melts to form water.

• Carbon dioxide freezes to form dry ice.

• Salt and water mix to form salt water.