Bond Energy(General Knowledge > General Science ) Questions and answers for exam Preparation

Question 1. Which is an example of an endothermic physical reaction?

Ice melting
Combustion
Steam condensing
Photosynthesis

Explanation:-

Answer: Option A. -> Ice melting

Question 2. How many electrons are shared in one chemical bond?

2
4
6
8

Explanation:-

Answer: Option A. -> 2

Question 3. How can we figure out if an overall reaction is endo- or exo-thermic? It is the difference between _______ and __________

hot and cold temperatures
energy to break and energy to form bonds.
time to form a bond versus time to break a bond
None of these

Explanation:-

Answer: Option B. -> energy to break and energy to form bonds.

Question 4. How many valence electrons do most electrons want in their valence shell to be stable? (Except hydrogen!)

2
4
6
8

Explanation:-

Answer: Option D. -> 8

Question 5. When bonds are _________, energy is released

formed
exothermic
Both A & B
All of above

Explanation:-

Answer: Option A. -> formed

Question 6. True or false: when bonds are broken the energy is positive because energy goes into the system

True
False

Explanation:-

Answer: Option A. -> True

Question 7. This is the number of years that Kuppler has been teaching at Kingsway:

3 years
5 years
9 years
10 years

Explanation:-

Answer: Option C. -> 9 years

Question 8. Which statements about exothermic reactions are correct?I

I and II only
I and III only
II and III only
I, II, and III

Explanation:-

Answer: Option D. -> I, II, and III

Question 9. What kind of energy change happens in the photosynthesis reaction in plant leaves?

Endothermic
Exothermic
No change
Both A & B

Explanation:-

Answer: Option A. -> Endothermic

Question 10. How can you determine an atom's valence electrons?

the column on the periodic table
the row on the periodic table
the atomic number
the atomic mass

Explanation:-

Answer: Option A. -> the column on the periodic table