Ch 8 - Periodic Properties of the Elements

Question 1

Periodic Property

Answer 1

a property of an element that is predictable based on the elements position within the periodic table.

Question 2

Dmitri Mendeleev

Answer 2

credited for the creation of the modern periodic table.

Question 3

Periodic law

Answer 3

when elements are arranged in order of increasing mass(later corrected to atomic number not mass) certain properties recur periodically.

Question 4

Electron Configuration

Answer 4

shows the particular orbitals that electrons occupy for an atom.

Question 5

Ground State

Answer 5

the lowest energy state of an electron.

Question 6

Orbital Diagram

Answer 6

symbolizes the electron as an arrow and the orbital as a box(half an arrow up and half and arrow down = 2 electrons with different spins)

Question 7

Pauli Exclusion princple

Answer 7

Wolfgang Pauli.

No two electrons in an atom can have the same four quantum numbers(m,n,ml,and ms)

If two electrons are in the same orbital then they have different spins(+1/2 and -1/2 for ms)

Question 8

Degenerate

Answer 8

in a hydrogen atom the empty energy levels have the same energy.

Question 9

Not degenerate

Answer 9

in multi electron atoms the energy of electrons in orbits within a principal level depends on the value of “l”.

Generally the lower the value of “l” the lower the level of E.

E(s orbital) < E(p orbital) < E (d orbital) < E (f orbital)

Question 10

Coulombs law

Answer 10

the potential energy(E) of two charged particles depends on their charges(q1 and q2) and on their separation(r).

E = (1/(4pie(e0)))((q1q2)/r)

e0 = 8.85 * 1-^-12 C^2/(J)(m)

Question 11

Shielding

Answer 11

the repulsion of one electron by other electrons that screens or shields that electron from the full effects of the nuclear charge.

Question 12

effective nuclear charge(Zeff)

Answer 12

the difference between the nucleus and other electrons in the way of an electron feeling the charge from the nucleus.

3+ and 2-(shielding) = a net 1+ charge on an outer electron.

**Radius is constant for non main group elements because of shielding.

Question 13

Penetration

Answer 13

Occurs when an outer electron enters into the region occupied by the inner electrons and experiences a greater nuclear charge(based on less shielding from inner electrons). Subsequently the electron that penetrated has a lower energy(closer to nucleus)

Question 14

Paramagnetism

Answer 14

unpaired electrons aligned in the same direction.

Magnetic field

Question 15

Diamagnetism

Answer 15

paired electrons.

No magnetic field

Question 16

Zeff

Answer 16

basically just the number of valence electrons = charge experienced

Question 17

Size of an atom

Answer 17

Radius increases down a column

Radius increase from right to left across a period.

Rb larger. He Smaller.

Question 18

Ionization Energy

Answer 18

minimum amount of energy needed to remove an electron from an atom.

More energy from left to right on a period.

More energy from bottom to town of a colum.

He requires most energy to ionize.

Cs requires least energy.

ALWAYS ENDOTHERMIC(electron needs more energy to leave atom)

Question 19

Electron Addinity

Answer 19

the ability to gain an electron.

Generally, more negative(more energy required) from left to right.(halogens have highest EA)

5A lower EA than expected(extra electron must pair)

2A and 8A tend to have low EA(electron goes to higher energy level)

mostly EXOTHERMIC(take energy to add electrons)

Question 20

Metallic Character

Answer 20

how closely an elements properties match the ideal properties of a metal.

malleable, ductile, easy to ionize, and good conductors.

decreases from left to right.

Increases down a column.

Question 21

Size of ions

Answer 21

Cations: smaller than parent(less - to + = closer to nucleus)

Anion: larger than parent(more - to + = farther from nucleus)

Question 22

Lattice Energy

Answer 22

the energy required to completely separate a mole of a solid ionic compound into its gaseous ions.

Question 23

Crystal lattice

Answer 23

maximizes the attractions between cations and anions, leading to the most stable arrangement.