Chapter 7: Periodic Properties of the Elements

Question 1

Bombarded with high-energy electrons, each element produced x-rays of unique_____.

Answer 1

frequencies

Question 2

When bombarding elements with electrons, Moseley observed that as frequency increased, atomic mass___.

Answer 2

increased

Question 3

Coulomb’s law

Answer 3

The strength of the interaction between two electrical charges depends on the magnitudes of the charges and on the distances between them.

Question 4

As the nuclear charge between the nucleus and the electron increases, the force _____.

Answer 4

increased

Question 5

Each electron is _____ to the nucleus, and _____ by other electrons

Answer 5

attracted, repelled

Question 6

effective nuclear charge

Answer 6

Z_eff= Z - S

S- screening constant (positive number)

• represents the portion of the nuclear charge that is screened by electrons (including v. e-‘s)
• close to the number of core electrons in an atom

Question 7

For an atom with many electrons, the energies of the orbitals with the same principal quantum number increase with an increasing ‘l’ value. This is due to ________.

Answer 7

the radial probability functions for the orbitals

Question 8

The effective nuclear charge _____ from left to right across the periodic table.

Answer 8

increases

Question 9

Going down a column, the effective nuclear charge experienced by valence electrons changes _(more/less)_ than it does across a period.

Answer 9

less

-Going down column, nuclear charge increase slightly

Question 10

bonding atomic radius

Answer 10

the distance separating the nuclei when two atoms are bonded to each other

-is equal to half of the nucleus to nucleus distance in atom

Question 11

Going top to bottom down a group, bonding atomic radius ____.

Answer 11

increases

(due to increase in ‘n’ of the outer electrons)

-going down column, outer electrons are more likely farther from nucleus= increased atomic radius

Question 12

Going left to right across a period, bonding atomic radius ____.

Answer 12

decreases

-This is due to increase in effective nuclear charge, which draws the valence electrons closer to the nucleus.

Question 13

Cations are _(smaller/larger)_ than their parent atoms.

Answer 13

smaller

-electrons are removed, electron-electron repulsions are reduced

Question 14

Moving down a group in the periodic table, ionic radius ____.

Answer 14

increases

-because PQN of outermost occupied orbital of ion increases

Question 15

isoelectronic series

Answer 15

a group of ions containing the same number of electrons

Question 16

As electrons are removed from an atom, ionization energy _____.

Answer 16

increases

(harder to remove e-)

-ESPECIALLY when one of inner electrons is removed

Question 17

Moving left to right across the periodic table, ionization energy _____.

Answer 17

increases

Question 18

Moving down a group of the periodic table, ionization energy _____.

Answer 18

decreases

Question 19

Positive ionization energy means energy must be ___the atom to remove the electron.

Answer 19

put into

Question 20

electron affinity

Answer 20

• (How easily atom gains e-)
• the energy change that occurs when an electron is added to a gaseous atom
• measures attraction between atom and e-

Question 21

The greater the attraction between atom and added electron, the more ___ the atom’s electron affinity.

Answer 21

negative

Question 22

Metals

Answer 22

• shiny luster
• conduct heat and electricity
• malleable
• ductile
• solids at room temp.
• low ionization energy

Question 23

Metals are __(oxidized/reduced)__ during chem. reactions.

Answer 23

oxidized, lose e-s

Question 24

Non-metals

Answer 24

• not lustrous
• poor conductors of heat/electricity
• low melting points

Question 25

Nonmetals __(gain/lose)_ electrons when they react with metals.

Answer 25

gain

Question 26

Alkali metals

Answer 26

• high heat and electricity conductors
• low densities
• low melting points

Question 27

Alkali Earth Metals

Answer 27

• higher densities
• higher melting points