Question

note: to answer some of the questions, it may help to reference a periodic table
checkpoint 17
listen
what are signs that a chemical change has occurred?
(select all that apply)
change in temperature
change in shape
change in odor
change in state of matter

Explanation:

• A change in temperature can indicate a chemical reaction as energy is either absorbed (endothermic) or released (exothermic).
• A change in odor often occurs when new substances with different chemical properties (and thus different odors) are formed in a chemical change.
• A change in shape is a physical change (e.g., molding clay) and does not involve a chemical reaction.
• A change in state of matter (e.g., water freezing to ice) is a physical change as the chemical composition of the substance remains the same.

Answer:

change in temperature, change in odor