Chapter 1 Atomic Structure

Question 1

Mass Number

Answer 1

Sum of protons and neutrons in the atom’s nucleus

Question 2

Atomic Number (Z)

Answer 2

Number of protons found in an atom of an element

Question 3

Isotopes

Answer 3

Same atomic number, but different mass numbers

Different number of neutrons in nucleus

Question 4

Electrostatic Force

Answer 4

Force between charges of electrons and protons in the element. These forces are much stronger than those of gravity.

Question 5

Valence Electrons

Answer 5

Electrons in the outer shell that have the weakest interactions with the nucleus.

React with surrounding environment

Question 6

Atomic mass unit (amu)

Answer 6

Protons have a mass of approximately 1 amu

1/12 the size of a carbon-12 atom

nearly equally to mass number

Question 7

Cation

Answer 7

Positively charged atom

Question 8

Anion

Answer 8

Negatively charged atom

Question 9

Hydrogen Isotopes

Answer 9

Protium- 1
Deuterium-2
Tritium-3

Question 10

Atomic Weight

Answer 10

Weighted average of the various isotopes

Question 11

Avogadro’s Number

Answer 11

6.02 x 10^23 carbon atoms = 12 g

Question 12

Ground State

Answer 12

Atom in the state of lowest energy

All electrons are in the lowest possible orbitals

Atoms on MCAT will most likely be in this state unless otherwise indicated

Question 13

Excited State

Answer 13

At least one electron has moved to a sub-shell of higher than normal energy.

Question 14

Line Spectrum

Answer 14

Each line on the emission spectrum corresponds to a specific electron transition

Question 15

Atomic emission spectrum

Answer 15

Can be used to find which element is a certain emission

Lower to higher energy level: AHED
Absorb light, higher potential, excited, distant (from nucleus)

Question 16

Series

Answer 16

Lyman series: n>2 to n=1

Balmer Series: n>3 to n=2

Paschen Series: n>4 to n=3

Question 17

E=Rh[(1/ni^2)-(1/nf^2)]

Energy associated with a change in the principal quantum number

Answer 17

Emission: Positive
Absorption: Negative

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

Wavelengths of absorption=wavelengths of emission

Question 18

Orbitals

Answer 18

Where electrons are actually present

Question 19

Heisenberg uncertainty principle

Answer 19

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

Question 20

Pauli exclusion principle

Answer 20

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

Question 21

Principal quantum number

Answer 21

n

Larger the principal quantum number, the higher the potential energy and the larger the radius.

Question 22

Azimuthal (angular momentum) quatum number

Answer 22

l

=0 or (n-1)

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

Question 23

Spectroscopic notation

Answer 23

l=0 is called s
l=1 is called p
l=2 is called d
l=3 is called f

Question 24

Magnetic Quantum Number

Answer 24

ml

Specifies the particular orbital within a subshell where an electron is most likely to be found at a given moment in time

ml= 0 and -l to l

Question 25

Spin Quantum number

Answer 25

ms

+1/2 or -1/2

Whenever two electrons are in the same orbital they must have opposite spins=paired

Electrons in two different orbitals with the same ms values are said to have parallel spins.

Question 26

Aufbau principle (building up principle)

Answer 26

Each subshell will fill completely before electrons begin to enter the next one.

Question 27

n+l rule

Answer 27

The subshell with the lower value will fill first

Question 28

4l+2 rule

Answer 28

Number of electrons per subshell

Question 29

Hund’s rule

Answer 29

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

Question 30

Paramagnetic

Answer 30

Magnetic field causes attraction via parallel spins

Question 31

Diamagnetic

Answer 31

magnetic fields causes repulsion