Question

question 19 (1 point)
what happens to the overall energy in a reaction system when bonds are formed?
a energy is absorbed
b energy is released
c no energy change occurs
d no energy change occurs

question 20 (1 point)
what is the purpose of the incremental modeling tracker (imt)?
a to build physical models of molecules
b to track progress in understanding hydrogen combustion
c to calculate bond dissociation energies
d to document unrelated science experiments

question 21 (1 point)
what type of models are students asked to create to represent combustion reactions?
a computational models only
b physical (virtual)models only
c visual animations
d both physical (virtual) and computational models

Explanation:

For Question 19: Bond formation is an exothermic process, meaning energy is released from the system.
For Question 20: The Incremental Modeling Tracker (IMT) is a tool focused on tracking learning progress related to hydrogen combustion understanding.
For Question 21: Combustion reaction representation in academic settings often uses both virtual/physical and computational models to cover different aspects of the reaction.

Answer:

Question 19: b. Energy is released.
Question 20: b. To track progress in understanding hydrogen combustion
Question 21: d. Both physical (virtual) and computational models