chapter 3

Question 1

degenerate orbitals

Answer 1

orbitals of the same energy

Question 2

According to Hund’s rule, how are degenerate orbitals occupied?

Answer 2

degenerate orbitals are filled with one electron at a time shell by shell. Each part of each orbital gets a singular electron before the electrons begin to double up.

Question 3

What are valence electrons?

Answer 3

For main group elements, the valence electrons are the electrons in the unfilled outermost energy shell. for the d block elements, they are the the unfilled shells electrons and the electrons in the outermost shell.

Question 4

Why are valence electrons important?

Answer 4

The chemical properties of an element depend on their valence electrons. These electrons are used in bonding since they are in the outermost shell and are the easiest to lose or share.

Question 5

Explain the relationship between a main-group element’s lettered group number (the number of the element’s column) and its valence electrons.

Answer 5

The lettered group number of a main-group element is equal to the number of valence electrons for that element.

Question 6

Describe the relationship between the radius of a cation and that of the atom from which it is formed.

Answer 6

cations are much smaller than their corresponding parent

Question 7

Describe the relationship between the radius of an anion and that of the atom from which it is formed.

Answer 7

anions are much larger than their corresponding parent

Question 8

Give the number of valence electrons for alkali metals

Answer 8

1

Question 9

Explain the relationship between the number of valence electrons and the resulting chemistry of alkali metals.

Answer 9

alkali metals are considered the most reactive elements on the periodic table. This is because they have one valence electron. They are able to easily lose this to become like noble gasses. they commonly form noble gasses.

Question 10

Give the number of valence electrons for alkaline earth metals.

Answer 10

These elements only have 2 valence electrons which they easily lose to become +2 cations. This makes them very willing to bond. Similarly they are less reactive than the alkali metals due to the fact that they have a full s orbital.

Question 11

ve the number of valence electrons for halogens.

Answer 11

Halogens have 7 valence electrons. This makes them very willing to share an electron since they are so close to a noble gas. they will form a -1 anion.

Question 12

Give the number of valence electrons for oxygen family.

Answer 12

Oxygen family elements have 6 valence electrons which means that they are quite close to the noble gasses. This means that they are very willing to share 2 electrons and form a -2 anion.`

Question 13

what is the trend of atomic radius

Answer 13

as you move to the right the size decreases

as you move down the size increases

Question 14

What is ionization energy?

Answer 14

the energy required to remove an electron from the atom or ion in the gaseous state

Question 15

What is the difference between first ionization energy and second ionization energy?

Answer 15

The second IE is always greater than the first IE

Question 16

What is electron affinity?

Answer 16

energy change associated with the gaining of an electron by the atom in the gaseous state. how likely it is to gain another electron

Question 17

What are the observed periodic trends in electron affinity?

Answer 17

for main-group elements, electron affinity generally becomes more negative as you move to the right across a row
there is not a corresponding trend in electron affinity going down a column

Question 18

zeff

Answer 18

Z- summation of s’s(effectiveness)
z=atomic number
s=number of shielding electrons

Question 19

n effectiveness

Answer 19

.35

Question 20

n-1 effectiveness

Answer 20

0.85

Question 21

n-2 effectiveness

Answer 21

1.0

Question 22

n-3 effectiveness

Answer 22

1.0

Question 23

zeff definition

Answer 23

effective nuclear charge on the valenece electrons

Question 24

what is the most stable electron configuration

Answer 24

having s and p filled

Question 25

ionic radius

Answer 25

the radius of an ion

Question 26

ionic radius trend

Answer 26

increases up and to the left

Question 27

ionization energy trend

Answer 27

increases up and to the right

Question 28

zeff trend

Answer 28

increases up and right

Question 29

explain the atomic radius trend

Answer 29

as we go down the radii increase because there are new shells and orbitals

as we go right the size decreases because Zeff increases

Question 30

explain the Zeff trend

Answer 30

as we go down a group zeff will decrease because there are more shielding orbitals

it increases as we go right across because of the increase in nuclear charge without the increase of shielding orbitals

Question 31

explain ionization energy trend

Answer 31

as we move down a group it becomes easier to remove an eectron because zeff decreases and there are more shielding electrons

as we move to the right zeff increases so generally it will be harder to remove an electron. this is

Question 32

why are there exceptions to the ioniuzation trend

Answer 32

there is a balancing effect of having a full s or p orbital half full as well

Question 33

explain the trends in electron affinity

Answer 33

as we move theo the right the elements get closer to noblke gasses what make them more likely to steal an elefctron

Question 34

what is atomic radius

Answer 34

The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding cloud of electrons.

Question 35

ionic radius

Answer 35

The ionic radius is half the distance between two gas atoms that are just touching each other. In a neutral atom, the atomic and ionic radius are the same, but many elements exist as anions or cations. If the atom loses its outermost electron (positively charged or cation), the ionic radius is smaller than the atomic radius because the atom loses an electron energy shell.

If the atom gains an electron (negatively charged or anion), usually the electron falls into an existing energy shell so the size of the ionic radius and atomic radius are comparable.