Chapter 3

Question 1

A periodic property

Answer 1

one that is generally predictable based on an element’s position within the periodic table.

Question 2

periodic law

Answer 2

When the elements are arranged in order of increasing mass, certain sets of properties recur periodically.

Question 3

family or group

Answer 3

elements have similar properties

Question 4

electron configuration

Answer 4

shows the particular orbitals that electrons occupy for that atom

Question 5

ground state

Answer 5

lowest energy state

Question 6

Pauli exclusion principle

Answer 6

No two electrons in an atom can have the same four quantum numbers.

Question 7

degenerate

Answer 7

describes two or more electron orbitals with the same value of n that have the same energy

Question 8

shielding

Answer 8

For multi-electron atoms, any single electron experiences both the positive charge of the nucleus (which is attractive) and the negative charges of the other electrons (which are repulsive).

Question 9

effective nuclear charge

Answer 9

the difference of the protons and core electrons

Question 10

aufbau principle

Answer 10

The pattern of orbital filling

Question 11

Hund’s rule

Answer 11

when filling degenerate orbitals, electrons fill them singly first, with parallel spins

Question 12

valence electrons

Answer 12

For main-group elements, the valence electrons are those in the outermost principal energy level

Question 13

core electrons

Answer 13

those in complete principal energy levels and those in complete d and f sublevels.

Question 14

noble gases

Answer 14

generally inert—they are the most unreactive elements in the entire periodic table. In other words, when a quantum level is completely full, the overall potential energy of the electrons that occupy that level is particularly low.

Question 15

Metals

Answer 15

lie on the lower left side and middle of the periodic table and share some common properties

Question 16

Nonmetals

Answer 16

lie on the upper right side of the periodic table. The division between metals and nonmetals is the zigzag diagonal line running from boron to astatine.

Question 17

metalloids

Answer 17

elements that lie along the zigzag diagonal line that divides metals and nonmetals

Question 18

alkali metals

Answer 18

all have an outer electron configuration of ns^1. Like sodium, a member of this family, the alkali metals have electron configurations that are one electron beyond a noble gas electron configuration

Question 19

alkaline earth metals

Answer 19

all have an outer electron configuration of ns^2. They have electron configurations that are two electrons beyond a noble gas configuration.

Question 20

halogens

Answer 20

all have an outer electron configuration of np^5. Like chlorine, a member of this family, their electron configurations are one electron short of a noble gas configuration.

Question 21

atomic radius

Answer 21

As we move down a column (or family) in the periodic table, the atomic radius increases.

As we move to the right across a period (or row) in the periodic table, the atomic radius decreases

Question 22

paramagnetic

Answer 22

an atom or ion that contains unpaired electrons is attracted to an external magnetic field

Question 23

diamagnetic

Answer 23

An atom or ion in which all electrons are paired is not attracted to an external magnetic field—it is instead slightly repelled

Question 24

Cations and radius

Answer 24

Cations are much smaller than their corresponding neutral atoms

Question 25

Anions and radius

Answer 25

Anions are much larger than their corresponding neutral atoms.

Question 26

isoelectronic series

Answer 26

ions with the same number of electrons.

Question 27

ionization energy

Answer 27

the energy required to remove an electron from the atom or ion in the gaseous state. Ionization energy is always positive because removing an electron always takes energy.

Question 28

Trends in First Ionization Energy

Answer 28

First ionization energy starts at a minimum with each alkali metal and rises to a peak with each noble gas.

First ionization energy generally decreases as we move down a column (or family) in the periodic table because electrons in the outermost principal level are increasingly farther away from the positively charged nucleus and are therefore held less tightly.

First ionization energy generally increases as we move to the right across a row (or period) in the periodic table because electrons in the outermost principal energy level generally experience a greater effective nuclear charge .

Question 29

electron affinity (EA)

Answer 29

the energy change associated with the gaining of an electron by the atom in the gaseous state.

Question 30

Metallic Character

Answer 30

As we move to the right across a row (or period) in the periodic table, metallic character decreases.

As we move down a column (or family) in the periodic table, metallic character increases.