2.3 Electron Configurations

Question 1

How are electrons arranged in an atom?

Answer 1

Energy levels round nucleus.

Question 2

How are the maximum number of electrons in each main energy level found?

Answer 2

2n^2 where n is the number of main energy level.

Question 3

What are the main energy levels divided up into?

Answer 3

Sub shells - s, p, d, f

Question 4

What are the maximum number of electrons in each sub shell?

Answer 4

s - 2
p - 6
d - 10
f - 14

Question 5

Within any main ever level what is the ordering of the sub levels?

Answer 5

s < p < d < f

Question 6

Which sub level is lower in energy than the 3d sub level.

Answer 6

4s

Question 7

What are condensed electron configurations?

Answer 7

Electron configuration of previous noble gas is assumed and everything after that is given in full.

Question 8

What are the two exceptions in electron configuration?

Answer 8

Copper and Chromium - instead of having normal electron configurations they only have one electron in the 4s sub level.

Question 9

What is the electron configuration of copper?

Answer 9

Cu: 1s2 2s2 2p6 3s2 3p6 3d5 4s1

Question 10

What is the electron configuration of chromium?

Answer 10

Cr: 1s2 2s2 2p6 3s2 3p6 3d10 4s1

Question 11

What is an orbital?

Answer 11

A region of space where there is a high probability of finding an electron.

Question 12

What energy does an orbital represent?

Answer 12

Each orbital represents a discrete energy level.

Question 13

How many electrons can an orbital contain?

Answer 13

A maximum of two electrons with opposite spins.

Question 14

What are the shapes of s and p orbitals?

Answer 14

s is spherical

p is dumbbell shape

Question 15

How are the p orbitals arranged?

Answer 15

px points along x axis
py points along y axis
pz points along z axis

Question 16

What is each sub level made up of?

Answer 16

A set of degenerate orbitals.

Question 17

What does an orbital diagram show?

Answer 17

Electrons as single headed arrows in boxes, each box represent an orbital. Arrows point either up or down representing electrons spinning in opposite directions.

Question 18

What is the Pauli exclusion principle?

Answer 18

Maximum number of electrons in an orbital is two - if there are two electrons in an orbital they have opposite spin..

Question 19

What is Hund’s rule?

Answer 19

Electron fill orbitals of same energy as to give the maximum number of elections with spins the same.

Question 20

What happens for electron configuration of positive ions?

Answer 20

Highest energy electrons are removed first.

Question 21

What happens for the electron configuration of positive ions for transition metals and elements in group 13 and 14?

Answer 21

4s electrons and removed before 3d electrons.