Knowledge Check -- Chemical Properties and Changes

(a)   can be observed without changing the object or matter.

• Chemical Properties

• Chemical Changes

• Physical properties
• Physical Changes

Which of the following is an example of a physical property?

• Reactivity with other chemicals

• Flammability

• Toxicity

• Color

What is a physical change?

• A change in color, odor, or temperature

• A change in the molecular composition of a substance

• A change in state from solid to liquid

• A change in reactivity with other chemicals

​ (a)   Physical Changes are reversible

• True
• False

​ ​ ​ ​ ​ (a)   ​ cannot be determined by touching or viewing a sample, they can only be observed by

changing the substance.

• Chemical Properties
• Chemical Changes

• Physical Changes

• Physical properties

Which of the following is a chemical property?

• Density

• Brittleness

• Oxidation

• Solubility

What is a chemical reaction?

• A change in color, odor, or temperature

• A change in state from solid to liquid

• A process where new substances are formed

• A process where physical properties are altered

What are the signs that a chemical reaction has occurred?

(Select all that apply)

• Change in color, odor, or temperature

• Formation of bubbles or gas

• Production of light

• Volume

Are all chemical reactions violent and explosive?

• Yes, all chemical reactions are violent and explosive

• No, chemical reactions can be slow and nonexplosive

• Only reactions involving gases are violent and explosive

• Chemical reactions are always unpredictable

There are 3 signs that indicate a chemical reaction occuring​ ​ (a)   , ​ (b)   , and ​ (c)  

• color
• odor
• temperature
• hardness
• Density