Lesson 2

Question 1

iClicker: An atom has 7 valence electrons. Is it more likely to gain or lose electrons?

Answer 1

Gain

Question 2

iClicker: An atom gains an electron. Is it more positive or negative?

Answer 2

Negative

Question 3

iClicker: Under what conditions are you able to count electrons to determine the identity of an atom?

Answer 3

If the atom is neutral

Question 4

iClicker: Based on electronegativity, what can you predict about the polarity of water molecules (H2O)?
Atoms/electronegativity:
O - 3.5
N - 3.0
C - 2.5
H - 2.1

Answer 4

They are strongly polar, strong pull on electrons by oxygen

Question 5

iClicker: Which of the following is not true about a change in pH from 7.0 to 6.0?

a. The solution becomes more acidic
b. The partial hydrogen ion concentration increases
c. The partial hydrogen concentration decreases from 10^-6 mol/L to 10^-7 mol/L
d. The solution is not longer neutral

Answer 5

C

Question 6

iClicker: Acid rain has a pH of 4 compared to the normal pH of 6. Acid Rain the had ____ fold ____ H+ concentration.

a. 100, lower
b. 10, lower
c. 10, higher
d. 100, higher

Answer 6

D

Question 7

HW: As the concentration of hydronium ions increses, the pH of the solution ____.

Answer 7

Decreases

Question 8

Beaker A has a greater concentration of hydroxide ions than Beaker B. Beaker B has a greater concentration of hydronium ions than Beaker A. This means that the pH of the solution in Beaker A should be ____ than the pH of the solution in Beaker B.

Answer 8

Greater

Question 9

A solution has an initial pH of 5, which is considered to be acidic. This solution undergoes a change and the new pH is 6. Which of the following is true about this change?
There was a ____ fold ____ in [H+].

Answer 9

10, Decrease

Question 10

Bromine:
Br
AN: 35
AW: 79.904
Electrons: ??
Protons: ??
Neutrons: ??

Answer 10

Electrons: 35
Protons: 35
Neutrons: 45