Cem 141-Exam 1 Updated Questions And Correct Answers

CEM 141-EXAM 1 UPDATED QUESTIONS AND CORRECT
ANSWERS
Question:
1. Matter is made up of
Answer:
Atoms

Question:
2. The the smallest dis-tinguishable part of an element
Answer:
Atom

Question:
3. Can change over-time according to the evidence avail-able
Answer:
Theories

Question:
4. ALL atoms/mole-cules attract to one another due to
Answer:
Electrostatic forces

Question:
5. ________ lower po-tential energy of a system
Answer:
Attractions

Question:
6. _____ raise potential energy of a system
Answer:
Repulsions

Question:
7. Stable systems form where
Answer:
The attractive and repulsive forces are EQUAL or the potential energy is at a minimum

Question:
8. The most stable part of a graph is
Answer:
The well

Question:
9. The temperature of a phase change de-pends on

, Answer:
The strength of the inter molecular forces

Question:
10. Why do two isolated atoms attract each other as they ap-proach and repel af-ter coming too close
together?
Answer:
?

Question:
11. Predict and ex-plain the changes in the potential ener-gy, the kinetic ener-gy and the total en-ergy
as two isolat-ed helium (or anoth-er noble gas) atoms approach each oth-er.
Answer:
?

Question:
12. Construct a di-agram/picture and use it to explain how energy is trans-ferred at the atom-ic level
(by collisions that can either add energy to the sys-tem or remove it)
Answer:
?

Question:
13. Predict/rank the rel-ative London Dis-persion Forces be-tween atoms and molecules of differ-ent
sizes
Answer:
?

Question:
14. ?Relate the strength of London Disper-sion Forces to rel-ative melting and boiling points for the
noble gases or simple diatomic molecules (H2, N2, O2,F2, Cl2, Br2, and I2)
Answer:
?

Question:
15. List all the diatomic molecules
Answer:
H2, N2, O2, F2, Cl2, Br2, I2

Question:
16. Contrast the ener-gy change that oc-curs when two heli-um atoms or two hy-drogen atoms
com-bine
Answer:
?

Question:
17. Differentiate be-tween London Dis-persion Forces and covalent bonding