Question

A)
Why is thermal energy a good source of activation energy?
(1 point)
Thermal energy causes increased molecular movement, so molecules are more likely to make contact withone another.
Thermal energy causes decreased molecular movement, so molecules are less likely to make contact withone another.
Thermal energy causes chemical bonds to melt.
Thermal energy causes chemical bonds to form.
A)
A gas stove burns propane and oxygen to produce carbon dioxide and water, thereby heating ahome (i.e., the surroundings). Where is the source of the heat coming from?
(1 point)
The breaking of propane and oxygen bonds releases heat energy.
The formation of carbon dioxide and water releases heat energy.
The fire applied to burn propane releases heat into the home.
The gases formed absorb heat and distribute it throughout the home.

Answer 1

Q1 — Correct answer: Thermal energy causes increased molecular movement, so molecules are more likely to make contact with one another.
Explanation: Higher thermal energy increases molecular speed and collision frequency/energy, making it more likely collisions overcome the activation barrier.

Q2 — Correct answer: The formation of carbon dioxide and water releases heat energy.
Explanation: Bond breaking requires energy, but the formation of the new bonds in CO2 and H2O releases more energy than was consumed, so the net reaction is exothermic and heats the surroundings.