Chapter 1: Atomic Structure

Question 1

What are the three major subatomic particles?

Answer 1

Protons, neutrons and electrons

Question 2

What is an amu?

Answer 2

Atomic mass unit

Equal to the mass of approximately one proton

Question 3

What is the unique identifier for each element?

Answer 3

The atomic number, which is equal to the number of protons found in an atom of that element.

Question 4

How does a neutrons mass differ from the mass of a proton?

Answer 4

Neutrons and protons have approximately the same mass (neutrons are actually slightly larger)

Question 5

Atoms of the same element always have the same number of _______ , but can have different numbers of ________ .

Answer 5

Atoms of the same element always have the same number of PROTONS, but can have different numbers of NEUTRONS.

Question 6

What are valence electrons?

Answer 6

The electrons in the outermost energy level, which experience the least electrostatic draw to their nucleus

Involved in bonds and reactions

Question 7

What is atomic weight?

Answer 7

The mass in grams of one mole of atoms of a given element

Unit: g/mol

Question 8

How are grams and amu related?

Answer 8

1g = 1 mole of amu

Question 9

What are the three main isotopes of Hydrogen?

Answer 9

Protium: 1 proton, 0 neutron

Deuterium: 1 proton, 1 neutron

Tritium: 1 proton, 2 neutrons

Question 10

Describe weighted averages of masses listed on the periodic table

Answer 10

The atomic masses are calculated from the relative abundance of each isotope of an element.

%Abundance1(mass1)+%Abundance2(mass2) … = atomic weight

Question 11

What is Planck’s quantum theory?

Answer 11

Energy emitted as electromagnetic radiation from matter comes in discrete bundles called quanta.

E = h*f

h= Planck’s constant = 6.626*10^-34 J*s

f= frequency of radiation

E= energy value

Question 12

What is Bohr’s equation for angular momentum of an electron?

Answer 12

L = nh/2π

n= quantum number

h = Planck’s constant

Question 13

How does the energy of an electron change with respect to the quantum number?

Answer 13

It changes in discrete amounts according to:

E = -R_H/n²

R_H= Rydberg constant = 2.18 x 10^-18

“The energy of an electron increases the further out from the nucleus that it is located”

Question 14

Describe the emission spectra of atoms

Answer 14

Electrons are excited to different energy levels. When they return to their ground state, each will emit a photon with a wavelength characteristic of the specific energy transition that it undergoes

E = hc/λ

λ = wavelength of the radiation

Question 15

How are emission spectra useful for studying elements?

Answer 15

Each elements’ electrons can be excited to distinct energy levels, which causes each element to have unique line spectra

Question 16

What is the Balmer series?

Answer 16

The group of hydrogen emission lines corresponding to transitions from the upper energy levels n>2 to n =2

Question 17

What is the Lyman series?

Answer 17

Hydrogen emission lines corresponding to transitions from the upper levels n>1 to n=1

*Larger energy transitions, thus smaller wavelengths in the UV region, than the Balmer series

Question 18

Combining Bohr’s equation with Planck’s equation tells us what?

Answer 18

The energy of the emitted photon corresponds to the precise difference in energy between the higher-energy initial state and the lower-energy final state

E = hc/λ = -R_H* [1/n_i² - 1/n_f²]

Question 19

What is the Heisenberg uncertainty principle?

Answer 19

It is impossible to simultaneously determine, with perfect accuracy, the momentum and the position of an electron.

Question 20

What are the four quantum numbers?

Answer 20

Principal: n

Azimuthal: l

Magnetic: m_l

Spin: m_s

Question 21

What is the Pauli exclusion principle?

Answer 21

No two electrons in a given atom can possess the same set of four quantum numbers

Question 22

Describe the principal quantum number, n

Answer 22

Can take on any positive intiger value

Larger value means higher energy level, larger radius

Question 23

What is the electron capacity of a specific shell with a given n value?

Answer 23

2n²

Question 24

Describe the aximuthal quantum number

Answer 24

Angular momentum

Refers to the shape and number of subshells within a given principal energy level

Possible values: 0 to (n-1)

Question 25

What are the subshells l=0, l=1, and l=2 more commonly called?

Answer 25

s, p, and f

Question 26

What is the maximum number of electrons that can exist within a given subshell?

Answer 26

4*l + 2

l=aximuthal quantum number

Question 27

What is the shape of the p-orbitals?

Answer 27

Dumbell shaped

Question 28

Describe the magnetic quantum number

Answer 28

Specifies the particular orbital within a subshell where an electron is highly likely to be found

Possible values: integers from -l to l

Question 29

Describe the spin quantum number

Answer 29

Electrons have two possible spin orientations: +1/2 and -1/2

Electrons with parallel spins have the same m_s

Question 30

Describe the electron configuration notation (ex: 2p⁴)

Answer 30

The first number denotes the principal energy level, the letter designates the subshell, and the superscript gives the number of electrons in that subshell.

Question 31

What is the n+l rule?

Answer 31

For the order that electrons fill into subshells.

The lower the sum of the values of the first and second quantum numberes (n+l), the lower the energy of the subshell.

Question 32

Flowchart for electron energy levels

Answer 32

Question 33

What is Hund’s Rule?

Answer 33

Within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with parallel spins

Question 34

What is the difference between paramagnetic and diamagnetic materials?

Answer 34

Paramagnetic materials are made of atoms with unpaired electrons that orient their spins in alignment with the magnetic field.

Diamagnetic materials are made of atoms that have all paired electrons, and are slightly repelled by magnetic fields