Chemistry

Question 1

Shielding

Answer 1

Amount of shielding the highest energy electron feels is determined by number of filled shells in that atom (inner core atoms), as well as subshells within an energy level

2 Elements in the same row has same number of inner core electrons. However, highest energy electrons in the p subshell are shielded by s subshell.

More shielding=more to the right.

Question 2

Ionic Force with an Ion

Answer 2

Coulomb’s law
kqq/(r^2), so strongest ionic force will be with smallest radius, and largest charge.
(i.e. Magnesium has smaller radius than calcium, and higher charge than potassium

Question 3

Ionization Energy

Answer 3

Opposite to radius
Atoms and ions with valence electrons close to the nucleus require more energy, than farther
Up, and to the right.

Smaller one will have greater ionization energy in column.

Question 4

Fusion

Answer 4

Melting

Question 5

STP

Answer 5

0C, 1atm, 1 mol 22.4L

Question 6

Hybridization of central atom

XeOF4

Answer 6

O
F  Xe  F 
F   **   F 
five bonds and 1 lone electron pair=6 electron groups
Needs 6 hybrid orbitals
1S, 3P, 2D
sp3d2

Question 7

electron capture

Answer 7

addition of an electron to the nucleus

proton becomes a neutron

Question 8

Calculate energy required to cool (to boiling point)

Answer 8

q=mc(T)

Cgas=from gas to liquid

Question 9

Beta Decay

Answer 9

Weak Nuclear Force
Beta- decay
Beta+ decay
Electron capture

Question 10

Beta- Decay

Answer 10

Too many neutrons in nucleus
Converts neutron into proton and electron (B- particle)
MCAT: beta decay, usually means Beta- Decay
Decrease Neutron, Increase Proton

Question 11

Beta + Decay

Answer 11

Too FEW neutrons in nucleus
Converts Proton into Neutron and a Positron
Increase Neutron, Decrease Proton

Question 12

Electron Capture

Answer 12

Increase number of neutrons by capturing electron from the closes electron shell (n=1 shell)
Increase Neutrons, Decrease Protons

Question 13

Electron configuration

Answer 13

4s is higher than 3d so when ionizing, remove from 4s
Exceptions are 4/10d and 9/10d, they steal an electron from 4s
don’t forget f-group

Question 14

of neutrons

Answer 14

Mass - Protons

isotopes

Question 15

Gas Solubility

Answer 15

Gases become less soluble as temperature increases

Question 16

Phase change

Answer 16

Temperature remains constant

Question 17

How many orbitals occupy f-subshell?

Answer 17

7!!!

one s orbita, 3 p orbitals, etc. Each orbital can hold 2 electrons

Question 18

Car travelling at x m/s can stop at a distance dm with max deceleration. if the car is traveling at 2x m/s, what happens to the stopping time, stopping time and stopping distance

Answer 18

Stopping distance quadruples
Vf^2-Vi^2=2ax

Stopping time doubles
Vf-Vi=at

Question 19

Wind blowing from the West means

Answer 19

It’s blowing to the East

Question 20

On a graph, when velocity is ______ , acceleration is _____, and the position should show a _____ line.

Answer 20

Velocity is INCREASING, Acceleration is CONSTANT, and position should be PARABOLIC