Atomic Structure

Question 1

Protons have a mass of approximately one ______ ______ _______.

Answer 1

Atomic mass unit (amu)

Question 2

The atomic number (Z) of an element is equal to the number of ______ found in an atom of that element.

Answer 2

Protons

Question 3

True or false: Together, the protons and neutrons of the nucleus make up almost the entire mass of an atom.

Answer 3

True. The mass of a single electron is negligible.

Question 4

What is the mass number (A) of an atom?

Answer 4

The sum of the protons and neutrons in an atom’s nucleus.

Question 5

What are isotopes?

Answer 5

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Question 6

Do electrons closer to the nucleus have more or less energy compared to electrons farther away from the nucleus?

Answer 6

Less energy

Question 7

Generally speaking, which electrons of an atom are involved in chemical bonding?

Answer 7

Valence electrons

Question 8

A positively charged atom is called a _____; a negatively charged atom is called a(n) ______.

Answer 8

Cation; anion

Question 9

True or false: The atomic mass of an atom (in amu) is essentially the same as its mass number.

Answer 9

True

Question 10

The weighted average of different isotopes is referred to as atomic ______. It is the number reported on the periodic table.

Answer 10

Weight

Question 11

What is the numerical value of Avogadro’s number?

Answer 11

6.02 x 10^23

Question 12

The _____ state of an atom is the state of lowest energy, in which all electrons are in the lowest possible orbitals.

Answer 12

Ground

Question 13

An atom is said to be in the ______ state when at least one electron has moved to a subshell of higher than normal energy.

Answer 13

Excited

Question 14

The group of hydrogen emission lines corresponding to transitions from energy levels n = greater than or equal to 2 to n= 1 is known as the ______ series.

Answer 14

Lyman

Question 15

The group of hydrogen emission lines corresponding to transitions from energy levels n = greater than or equal to 3 to n= 2 is known as the ______ series.

Answer 15

Balmer

Question 16

The group of hydrogen emission lines corresponding to transitions from energy levels n = greater than or equal to 4 to n= 3 is known as the ______ series.

Answer 16

Paschen

Question 17

Describe the Heisenberg uncertainty principle.

Answer 17

This principle states that it is impossible to simultaneously determine both the location and the momentum (energy) of an electron with perfect accuracy.

Question 18

According to the ______ ______ principle, no two electrons in a given atom can possess the same set of four quantum numbers.

Answer 18

Pauli exclusion

Question 19

What are the 4 quantum numbers that can be used to completely describe an electron?

Answer 19

1. n
2. l
3. m sub l
4. m sub s

Question 20

The first quantum number, the letter n, is commonly known as the _______ quantum number.

Answer 20

Principal quantum number. It can theoretically take on any positive integer value.

Question 21

The maximum number of electrons within a shell can be determined by what equation?

Answer 21

2n^2

Question 22

The second quantum number is called the _______ (angular momentum) quantum number and is designated by the letter l.

Answer 22

Azimuthal. It refers to the shape and number of subshells within a given principal energy level.

Question 23

The value of n limits the value of l in the following way: for any given value of n, the range of possible values for l is 0 to ______?

Answer 23

(n - 1)

Question 24

What formula determines the maximum number of electrons within a subshell?

Answer 24

4l + 2

Question 25

The third quantum number is the ________ quantum number. It specifies the particular orbital within a subshell where an electron is most likely to be found at a given moment in time.

Answer 25

Magnetic (m sub l)

Question 26

The possible values of m sub l are the integers between ____ and ____, including 0.

Answer 26

-l; +l

Question 27

True or false: Whenever two electrons are in the same orbital, they must have the same spins.

Answer 27

False. Two electrons in the same orbital must have opposite spins. In this case, they are often referred to as being paired.

Question 28

Electrons in different orbitals with the same m sub s values are said to have _______ spins.

Answer 28

Parallel

Question 29

The l = 0 subshell is called ____.

Answer 29

s

Question 30

The l = 1 subshell is called ____.

Answer 30

p

Question 31

The l = 2 subshell is called ____.

Answer 31

d

Question 32

The l = 3 subshell is called ____.

Answer 32

f

Question 33

Describe the shapes of the orbitals in the s and p subshells.

Answer 33

The orbitals in the s subshell are spherical, while the three orbitals in the p subshell are each dumbbell-shaped and align along the x-, y-, and z-axes.

Question 34

The fourth quantum number is called the _____ quantum number and is denoted by m sub s.

Answer 34

Spin

Question 35

What are the two spin designations for an electron?

Answer 35

+1/2 and -1/2

Question 36

Electrons fill from lower- to higher-energy subshells, according the ______ principle (also called the building-up principle).

Answer 36

Aufbau

Question 37

Electron configurations can be abbreviated by placing the ______ ______ that precedes the element of interest in brackets.

Answer 37

Noble gas

Question 38

Describe the process for determining the electron configuration of a cation.

Answer 38

1. Start with the configuration of the neutral atom. 2. Remove electrons from the subshells with the highest value for n first. 3. If multiple subshells are tied for the highest n value, then electrons are removed from the subshell with the highest l value among these.

Question 39

Orbitals fill according to what rule?

Answer 39

Orbitals fill according to Hund's Rule. This states that, within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with parallel spins.

Question 40

In terms of electron configuration, what types of orbitals have lower energies (higher stability) than other states?

Answer 40

Half-filled orbitals and fully-filled orbitals are more stable.

Question 41

Materials consisting of atoms that have only paired electrons will be slightly repelled by a magnetic field and are said to be _______.

Answer 41

Diamagnetic

Question 42

The valence electrons in Groups IA and IIA (Groups 1 and 2) are located where?

Answer 42

For these groups, the highest s subshell electrons are valence electrons.

Question 43

What are the valence electrons for Groups IIIA through VIIIA (Groups 13 through 18)?

Answer 43

The highest s and p subshell electrons are the valance electrons for these groups.

Question 44

In what subshells do we find the valence electrons for transition elements?

Answer 44

Their valence electrons are those in the highest s and d subshells, even though they have different principal quantum numbers.

Question 45

Where are the valence electrons for elements in the lanthanide and actinide series?

Answer 45

Their valence electrons are those in the highest s and f subshells, even though they have different principal quantum numbers.

Question 46

In the _____ model of the atom, a dense, positively charged nucleus is surrounded by electrons revolving around the nucleus in orbits with distinct energy levels.

Answer 46

Bohr

Question 47

The ______ ______ model posits that electrons do not travel in defined orbits but rather are localized in orbitals.

Answer 47

Quantum mechanical

Question 48

Which type of materials have unpaired electrons that align with magnetic fields, attracting the material to a magnet?

Answer 48

Paramagnetic