Atomic Structure and Periodic Trends

Question 1

What letter is given to denote atomic number

Answer 1

Z aka # protons in that element

Question 2

What letter is given to denote atomic mass

Answer 2

A

Question 3

In the Bohr Model of the atom, e- orbit at fixed distances from the nucleus. The distance between the orbits _____ (increases or decreases) with distance from the nucleus

Answer 3

decrease therefore the distance between n = 1 and n = 2 is larger than the distance between 2 and 3

Question 4

Electrons in an excited state can return to a lower energy orbit, emitting a ____ equal in energy to the energy difference between the energy levels

Answer 4

photon

Question 5

Distinguish between the hydrogen absorption spectrum and the hydrogen emission spectrum

Answer 5

H absorption: dark bands against a colorful background; signify which colors are absorbed by H; thus e- are gaining energy and are becoming excited H emission: bright colored bands against a dark background; signify which colors are emitted by H; thus e- are losing energy and becoming relaxed

Question 6

Equation for Energy

Answer 6

E = hf = hc/lambda

Question 7

What is the order of the electromagnetic spectrum from lowest to highest energy?

Answer 7

radio, micro, IR, ROYGBV, UV, Xray, gamma

Question 8

What number is denoted by the shell and subshell

Answer 8

shell = principle quantum number = n subshell = orbital type = s,p,d,f

Question 9

What is the Pauli Principle?

Answer 9

no two e- may be identical; this limits the occupancy of an orbital to a max of 2 e-, each with an opposite spin

Question 10

What is the Aufbau Principle?

Answer 10

e- are added to orbitals from lowest to highest energy; consequently, e- are first removed from orbitals from highest to lowest energy (starting with highest energy valence orbitals) exception: even though 3d is higher in energy than 4s, the valence 4s e- are removed before the non-valence 3d e-

Question 11

What is Hund’s rule?

Answer 11

e- fill degenerate orbitals with one e- per orbital before pairing i.e. px, py, and pz orbitals will each be filled with one e- with the same spin before a second e- with the opposite spin is added to fill each px, py, and pz orbital

Question 12

Chromium and copper both have anomalous e- configurations, [Ar]4s13d5 and [Ar]4s13d10 respectively. Why?

Answer 12

The d subshell is more stable when it is half filled or fully filled, and so will steal an e- from the 4s orbital to do so.

Question 13

Which ion is more stable, Fe2+ or Fe3+? Why?

Answer 13

Fe3+ is more stable because its e- configuration is [Ar]3d5, compared to Fe2+ which is [Ar]3d6

Question 14

____ e- shield the val e- from the full nuclear charge

Answer 14

core

Question 15

The nuclear charge experienced by a valence e- is called ____ _____ charge

Answer 15

effective nuclear charge, Zeff

Question 16

Moving L to R across a period, which of the following increase, decrease: 1) electrostatic attraction of val e- ______ 2) atomic radius _____ 3) ionization energy _____ 4) electron affinity _____ 5) electronegativity _____ 6) acidity level ______

Answer 16

1) decreases 2) decreases 3) increases 4) increases 5) increases 6) increases

Question 17

How does atomic radius change when moving from top to bottom down the periodic table?

Answer 17

increases

Question 18

How does ionization energy change when moving from top to bottom down the periodic table?

Answer 18

decreases

Question 19

How does electron affinity change when moving from top to bottom down the periodic table?

Answer 19

decreases

Question 20

How does acidity change when moving from top to bottom down the periodic table?

Answer 20

increases

Question 21

The ionic radius _____ (increases or decreases) with increasing negative charge

Answer 21

increases

Question 22

What is ionization energy?

Answer 22

the minimum amount of energy required to remove the outer most e- from an atom in its gaseous state

Question 23

As Fe increases, removal of e- requires ____ (less or more energy)

Answer 23

more

Question 24

How is ionization energy affected as the positive charge on a given ion increases?

Answer 24

ionization energy will also increase, as it will (in most cases) be harder to remove successive e- from the atom

Question 25

What is e- affinity?

Answer 25

the energy change when adding an e- to the valence shell of an atom in its gaseous state

Question 26

Most elements tend to ___ energy upon the addition of an e-

Answer 26

release

Question 27

As Fe increases, additional e- releases ____ (less or more) energy

Answer 27

more

Question 28

Elements with ____ configurations tend to require energy upon the addition of an e-

Answer 28

closed-shell or closed-subshell

Question 29

As Fe increases, the electronegativity (or ability to attract e- _____ (decreases or increases)

Answer 29

increases

Question 30

If energy is released when the e- is added, the usual convention is to say that the electron affinity is ____

Answer 30

negative

Question 31

If energy is required when the e- is added, the usual convention is to say that the electron affinity is ____

Answer 31

positive

Question 32

Which family group tends to have the largest negative electron affinity values?

Answer 32

Group 7: halogens

Question 33

Which 2 family groups tend to have the largest positive electron affinity values?

Answer 33

Group 1: alkaline earth metals Group 8: noble gases

Question 34

What is the structure of a binary acid?

Answer 34

HX

Question 35

Distinguish between alpha, beta, and gamma decay

Answer 35

alpha: emits an alpha particle (nucleus loses 2 p+ and 2 n); atomic # decreases by 2 and atomic mass # decreases by 4; alpha particles are relatively weak, as they can be stopped by skin or clothing beta: three types, all involve a conversion of a p+ into a n or vice versa (depending if nucleus has too many p+ or n); more dangerous than alpha particles d/t decreased mass and higher energy gamma: occurs when the overexcited nucleus returns to its ground state, releasing a gamma photon (which has no mass nor charge and is simply just an expulsion of energy); the most type of dangerous decay

Question 36

Distinguish between the 3 types of beta decay

Answer 36

B- decay: neutron converts into a p+ by releasing a B- particle (aka e- gets ejected); atomic # increases by one B+ decay: p+ converts into a neutron by emission of a positron (aka antiparticle, which is identical to an e-, but opposite charge); atomic number decreases by one electron capture: p+ converts into neutron by stealing an e- from the innermost shell; atomic number decreases by 1

Question 37

The shorter the half life, the ____ the decay constant, k

Answer 37

greater

Question 38

What is nuclear binding energy?

Answer 38

The energy released when individual nucleons are bound together to form the nucleus

Question 39

The ______ (lesser or greater) the nuclear binding energy per nucleon, the more stable the nucleus

Answer 39

greater

Question 40

what is mass defect?

Answer 40

Refers to the mass that is converted to energy by nucleons when they are bound together to form the nucleus. Therefore, the mass of the nucleus is less than the sum of all the masses of the individual nucleons. This difference is the mass defect.

Question 41

Equation for energy of a photon

Answer 41

E_photon = hf = hc/lambda

h = Planck’s constant = 6.63 x 10^-34 J·s

f = frequency

c = speed of light = 3 x 10⁸

lambda = wavelength

Note that Energy and frequency are inversely proportional to lambda/wavelength: the longer the wavelength, the less energy and less frequency of the photon

Question 42

All p orbitals of x, y, and z are known as degenerate orbitals. What does this mean it regards to their energy?

Answer 42

means that they are equal in energy

Question 43

What is effective nuclear charge, Z_eff

Answer 43

The nuclear charge experienced by a valence e-

Question 44

Moving from top to bottom of the periodic table, Z_eff and # of valence e- _____ (increases, decreases, or stays the same). What happens to the electrostatic attraction, F_e, going down a group in the periodic table and why?

Answer 44

1) stays the same
2) F_e decreases even though Z_eff remains constant because the size of the valence shell (r) increases. Coulombs law: F_e = (Z_eff + C)/r²

Question 45

Moving from L to R across the periodic table, the Z_eff and # of valence e- ______ (increase, decrease, or remains the same). How is F_e affected?

Answer 45

1) increase (this is because the size remains fairly constant; therefore the effective nuclear force decreases)
2) F_e increases because as Z_eff increases, the size of the valence shell stays the same

Question 46

How does atomic radius change moving from L to R accross a periodic table?

Answer 46

it decreases

Question 47

Distinguish between diamagnetic and paramagnetic

Answer 47

Dia: an atom that has all of its e- spin paired; therefore it must have an even number of e- AND have all of its occupied subshells filled. This creates no net magnetic field and these atoms are actually repelled by an applied external magnetic field

Para: an atom that doesn’t have all of its e- paired or subshells filled. These atoms will be attracted to an externally applied magnetic field.