Unit 2 Test

Question 1

what are periods

Answer 1

the rows on the periodic table

Question 2

what are groups

Answer 2

the columns on the periodic table

Question 3

what is the stair step line

Answer 3

the thick stair step line on the table that separates the metals from the non metals

Question 4

what are metals

Answer 4

shiny, very dense, and only melt at high temperatures
-shapes can easily be changed without breaking
-heat and electricity travel very quickly through metals
all the elements left of the stair step line except germanium, antimony, and polonium

Question 5

what are non-metals

Answer 5

dull and different from metals
-they don’t conduct heat and electricity
-they have low density and melt at low temperatures
-cannot change shape easily
elements including and right of carbon, phosphorus, selenium, iodine, and radon

Question 6

what are metalloids

Answer 6

have both properties of metals and nonmetals
-they can be shiny or dull and shape can be easily changed
-heat and electricity can travel through but not as quickly as in metals
first elements to the right of the stair step line and germanium, antimony, and polonium

Question 7

what is the s block

Answer 7

the block with the first two columns and helium

Question 8

what is the p block

Answer 8

the block from column 13 to 18 not including helium

Question 9

what are the representative elements

Answer 9

the p block and the s block

Question 10

what is the d block

Answer 10

the block from column 3 to 12

Question 11

what are the transition elements

Answer 11

the elements in the d block

Question 12

what is the f block

Answer 12

the lowest block in the table that isn’t connected to the whole table

Question 13

what are the inner transition elements

Answer 13

the elements in the f block

Question 14

who is Mendeleev

Answer 14

the scientist that created the first periodic table by atomic mass and by trends

Question 15

what is effective nuclear charge (zeff)

Answer 15

an estimate of the net electric field felt by an electron
z= number of protons
s= number of core electrons/shielding electrons
z-s=zeff

Question 16

as you go left to right on the periodic table what happens to the zeff

Answer 16

it increases because the number of protons increase so there is a greater zeff

Question 17

as you go top to bottom on the periodic table what happens to the zeff

Answer 17

it stays the same because while the number of protons increase so do the number of core electrons at the same rate so they balance each other out

Question 18

what is atomic radius

Answer 18

represents one half the distance between the nuclei of atoms held together by a bond

Question 19

as you go left to right on the periodic table what happens to the atomic radius

Answer 19

it decreases because there are more protons but there are still the same amount of electron shells, therefore the greater number of protons the greater the attractive force on the electrons which makes the atom smaller

Question 20

as you go top to bottom on the periodic table what happens to the atomic radius

Answer 20

it increases because every row adds a new electron shell so the electrons are farther away from the nucleus

Question 21

what is ionic radii

Answer 21

when atoms gain an electron(s), they become negatively charged anions (anions are larger than the corresponding neutral atom
when atoms lose an electron(s), they become positively charged cations (cations are smaller than the corresponding neutral atom)

Question 22

what is ionization energy

Answer 22

the energy required to remove an electron from the ground state of a gaseous atom or ion

Question 23

as you go left to right on the periodic table what happens to the ionization energy

Answer 23

it increases because there are more protons in the nucleus which increases the attractive force felt by the outer electrons making it harder to remove it

Question 24

as you go top to bottom on the periodic table what happens to the ionization energy

Answer 24

the number of shells increases which means the outer electrons are more likely to be found in orbitals further away, this makes them less attracted to the nucleus so they take less energy to remove

Question 25

what is successive ionization energies

Answer 25

removing a second (or third etc.) electron always requires even more energy than removing the first one because the atom gets smaller each time an electron is removed so it makes the outer electrons more attracted to the nucleus which makes it harder to get rid of

Question 26

what is electron affinity

Answer 26

the energy change that occurs when an electron is added to a gaseous atom

• a negative affinity indicates a high attraction for an electron (energy is released)
• a positive affinity indicates that an electron is not likely to be gained by the atom

Question 27

as you go left to right on the periodic table what happens to the electron affinity

Answer 27

it increases but it shows a lot more variation than the other trends

Question 28

summarize the electron affinity for a halogen versus a noble gas

Answer 28

halogens have highly negative electron affinities because they have the greatest attraction for electrons since they only need to gain one electron to reach a full outer shell
noble gases have positive electron affinities because they already have 8 (an octet) valence electrons and would have to add and electron to an unoccupied higher shell

Question 29

what is electronegativity

Answer 29

the ability of an atom in a molecule to attract electrons to itself (want more electrons)
-the most electronegative elements also have highly negative electron affinites (attraction for other elements) and high ionization energies (tendency to hold onto their own electrons)

Question 30

as you go left to right on the periodic table what happens to the electronegativity

Answer 30

it increases

Question 31

as you go top to bottom on the periodic table what happens to the electronegativity

Answer 31

it decreases

Question 32

what are alkali metals

Answer 32

the elements in the first column except helium

Question 33

what are alkaline earth metals

Answer 33

the elements in the second column

Question 34

what are the transition metals

Answer 34

the d block

Question 35

what are halogens

Answer 35

the elements in 17th column

Question 36

what are noble gases

Answer 36

the elements in the 18th column

Question 37

what are inhert gases

Answer 37

gas that has extremely low reactivity with other substances also known as the noble gases