Ch 4 Section 3

Question 1

The arrangement of electrons in an atom is known as the atoms

Answer 1

Electron configuration.

Question 2

Because atoms of different elements have different numbers of electrons a unique

Answer 2

Electron configuration exists for the atoms of each element

Question 3

Like all systems in nature electrons in atoms tend to

Answer 3

Assume arrangements that have the lowest possible energies

Question 4

The lowest energy arrangement of the electrons for each element is called they

Answer 4

Elements ground state electron configuration

Question 5

To build up electron configurations for the ground state of any particular atom

Answer 5

First the energy levels of the orbitals are determined

Then electrons are added to orbitals one by one according to three basic rules

Question 6

According to the aufbau principle an electron occupied the

Answer 6

Lowest energy orbital that can receive it

Shows the order in which electrons occupy orbitals

Question 7

Beginning with the third main energy level n = 3, the energies of sublevels in different main energy levels

Answer 7

Begin to overlap

Question 8

The 4s sublevel is lower in energy to the

Answer 8

3d sublevel

Question 9

4s sublevel is filled before an electrons

Answer 9

Enter the 3d orbitals

Question 10

Less energy is required for two electrons to pair up in the 4s orbital than for

Answer 10

Those two electrons to occupy a 3d orbital

Question 11

The second rule reflects

Answer 11

Importance of spin quantum number

Question 12

According to the Pauli exclusion principle no two electrons in the same atom can

Answer 12

Have the same set of four quantum numbers

Question 13

The two values of he spin quantum number reflect the fact that for

Answer 13

2 electrons to occupy the same orbital they must have opposite spin states

Question 14

Third rule requires placing as many

Answer 14

Unpaired electrons as possible in separate orbitals in the same sublevel

Question 15

In this way electron electron repulsion is

Answer 15

Minimized so that the electron arrangements have the lowest energy possible

Question 16

According to hunds rule orbitals of equal energy are each occupied by one electron before any orbital he

Answer 16

Occupied by a second electron and all electrons in singly occupied orbitals must have the same spin state

Question 17

Applying hunds rule shows that one electron will enter each of the three

Answer 17

P orbitals in a main energy level before a second electron entered any of them

Question 18

3 methods or notations are used to indicate

Answer 18

Electron configurations

Third notation is mostly used with elements of the third period and higher

Question 19

(Orbital notation) an unoccupied orbital is represented by a

Answer 19

Line with the orbitals name written underneath the line

Question 20

(Orbital notation) the lines are labeled with the

Answer 20

Principal quantum number and sublevel letter. 
Ex: orbital notation for helium 
He ⬆️⬇️
      -------
       1s

Question 21

Electron configuration notation eliminated the

Answer 21

Lines and arrows of orbital notation

Question 22

(Electron configuration notation) instead the number of k

Electrons in a sublevel is shown by

Answer 22

Adding a superscript to the sublevel designation

Question 23

In the first period elements (hydrogen and helium) electrons occupy

Answer 23

The orbital of the first main energy level

Question 24

According to the aufbau principle after the 1s orbital is filled the next electron occupies the

Answer 24

S sublevel in the second main energy level

Question 25

The highest occupied energy level is the electron containing main energy level with the

Answer 25

Highest principal quantum number

Question 26

Inner she’ll electrons are electrons that are not in the

Answer 26

Highest occupied energy level

Question 27

According to the aufbau principle the next electron must pair with another electron in one of the

Answer 27

2p orbitals as long as the spins of the paired electrons are opposite

Question 28

Atoms such as those of neon which have the s and p sublevels of their highest occupied level filled with eight electrons are said to

Answer 28

Have an octet of electrons

Question 29

After the outer octet is filled in neon the next electron enters the

Answer 29

S sublevel in the n= 3 main energy level

Question 30

The first 10 electrons in an atom of each of the third period elements have the

Answer 30

Same configuration as neon which allows us to use a shorthand notation for the configurations

Question 31

(Noble gas notation) the group 18 elements are called

Answer 31

Noble gases

Question 32

(Noble gas notation) to simplify notation of third period elements the symbol for neon is

Answer 32

Enclosed j square brackets and the rest of the configuration follows

Question 33

A noble gas configuration refers to an outer main energy level occupied

Answer 33

In most cases by eight electrons

Question 34

The fourth period begins by filling the

Answer 34

4s orbital, the empty orbital of lowest energy

Question 35

With the 4s sublevel filled the

Answer 35

4p and 3d sublevels sre the next available vacant orbitals

Question 36

The 3d sublevel is lower in energy than the

Answer 36

4p sublevel. Therefore the five 3d orbitals are next to be filled

Question 37

A total of 10 electrons can occupy the

Answer 37

3d orbitals

Question 38

Fourth period element configurations begin with

Answer 38

[Ar]

Question 39

According to hunds rule one electron is added to each of the three

Answer 39

4p orbitals before electrons are paired in any 4p orbital

Question 40

In the 18 elements of the fifth period sublevels fill in a similar manner as in

Answer 40

Elements of the fourth period but start at the 5s orbital instead of the 4s

Question 41

Successive electrons are added to the first to the 5s orbital then to the

Answer 41

4d orbitals and finally to the 5p orbitals

Question 42

The sixth period consists of

Answer 42

32 elements

Question 43

To build up electron configurations for the sixth period electrons are added first to the

Answer 43

6s orbital in cesium and barium. Then jn lanthanum an electron is added to the 5d orbital

Question 44

With cerium 4f orbitals

Answer 44

Begin to fill

Question 45

Next 5d orbitals are filled and the period is completed by filling the

Answer 45

6p orbitals

Question 46

Because the 4f and 5d orbitals are very close in energy number our deviations from the simple rules

Answer 46

Occur as these orbitals are filled

Question 47

The seventh period is

Answer 47

Incomplete and consists largely of synthetic elements

Question 48

The quantum model of the atom improves on the Bohr model because it

Answer 48

Describes the arrangements of electrons in atoms other than hydrogen