periodic table + periodic trends

Question 1

atom

Answer 1

neutral particle

basic building block of metal

Question 2

protons

Answer 2

p+

positively charged sub atomic particles

Question 3

neutrons

Answer 3

n o

neutral sub atomic particles

Question 4

nucleons

Answer 4

p+ and n o

sub atomic particles

Question 5

atomic number

Answer 5

z

number of protons

Question 6

mass number

Answer 6

A

no. of protons+ neutrons> nucleons

Question 7

isotopes

Answer 7

atoms of same element (same p+) w diff. mass numbers

have diff properties to og element

Question 8

ions and types

Answer 8

charged atoms

cations: + charged atoms, tend to lose e-
anions: - charged atoms,tend to gain electrons

Question 9

group 1

Answer 9

alkali metals
most reactive of all metals
reactivity increases down group
found in compounds
-have single valance e-
react with cold water producing hydrogen and hydroxide
soft + light grey

Question 10

group 2

Answer 10

alkaline earth metals
reactive
2 valance e-
-somewhat less reactive than group 1
all except Br react w cold water forming hydrogen and hydroxide
light grey, relatively soft
good conductors

Question 11

group 17

Answer 11

halogens
very reactive - found in compounfs
form salts when react w metals
have 7 valance e- — gain 1 e-
reactivity decreases down group -atomic radius increases

low melting points

Question 12

group 18

Answer 12

stable noble gases
unreactive- full valance energy levels
gases at room temo

Question 13

group similarities

Answer 13

same valance e- (of group no.)

elements have similar chem. properties

Question 14

metals

Answer 14

left side of periodic table up to and including post transition metals
few valance e-
lose e- — cations

Question 15

non metals

Answer 15

right side of periodic table + including metalloids
large no. of valance e-
accept/gain e- to complete energy level—anions

Question 16

atomic radius

Answer 16

distance of an atom from its nucleus to its outermost section

decreases as goes up descending periods

increases as goes left groups

Question 17

explainibg atomic radius across perioid

Answer 17

from left to right across a period, the net attraction force of the nucleus to each electron increases, as number of protons in the nucleus increases.

a greater force of attraction means a smaller distance between the nucleus+valance e- and a smaller atomic radius

Question 18

explaining atomic radius from top to bottom down a group

Answer 18

from top to bottom down a group the number of energy levels increases
more energy levels result in larger atomic racius

Question 19

valance electrons

Answer 19

e- in the outermost energy level

group number

Question 20

valance energy level

Answer 20

outermost energy level

energy levels=period number

Question 21

core electrons

Answer 21

e- in the full inner energy levels

Question 22

diatomics

Answer 22

N -F, F- I

Question 23

unpaired e-

Answer 23

e- of valance e- does not have partner e-

Question 24

lone pairs

Answer 24

paired e- of valance e-

Question 25

valency number

Answer 25

charge atom would have if it were an ion

to become stable

Question 26

end of metals

Answer 26

Al
Ge
Sb
Po

Question 27

ionisation energy

Answer 27

amount of energy required to remove 1 electron from single atom in gaseous phase

inversely proportional to atomic radius

if atomic radius larger-removing e- easier, e- further from positive nucleus

smaller the atom,closer e- is to nucleus, more tightly bound to nucleus, will require more energy

Question 28

first ionisation energy

Answer 28

energy required to remove first e-

Question 29

huge ionisation energy

Answer 29

removing core e-

Question 30

why is it harder to remove e- as atom becomes smaller

Answer 30

closeer to positive nucleus

requires a lot of energy

Question 31

ionisation energy from left to right across a period

Answer 31

from left to right across a period the net attraction force of the nucleus to each electron increases as the number of protons in the nucleus increases.
A larger force of attraction means a smaller distance between the nucleus and valance e- and a smaller atomic radius.

A large force of attraction means that more energy is required to overcome forces to remove e-.

Question 32

from top to bottom down a group

Answer 32

from top to bottom down a group the number of energy levels increases (increasing atomic radius)

valance electrons are increasingly shielded from the positive nucleus by core electrons

this results in a smaller/weaker force of attraction on each e-

a weaker force of attraction means that more energy is required to overcome forces to remove e-

Question 33

electron shielding

Answer 33

barrier of negative energy level shields charge of positive charge

inner energy levels shield the positive charge of nucleus on valance e-

Question 34

anomalies

Answer 34

things that don’t follow the trend

Question 35

anomalies in ionisation energy

boron +beryllium

Answer 35

In boron the valance e- to be removed is in a P orbital

this electron is further from the nucleus + experiences a weaker force of attraction to the positive nucleus

less energy required to remove this e-
(lower ionisation energy than expected)

Question 36

anomalies in ionisation energy

N to O

Answer 36

In oxygen, the valance e- to be removed is in a p orbital that already has an e-.
the valance e- is repelled slightly by this electron meaning less energy is required to remove it

Question 37

electron affinity

Answer 37

amount of energy released when e- is added to a single atom in the gaseous phase (nm gain).

atoms w a greater affinity for e- release more energy when they gain e-

trend same as ionisation energy

Question 38

electron affinity trends

Answer 38

from left to right across a period the number of protons in the nucleus increases
the affinty for an e- increases
more energy released when e- added

from top to bottom down a group the number of energy levels increases (increasing atomic radius)

more energy levels means more e- shielding of positive nucleus

affinity for e- decreases, less energy is released when e- added

Question 39

electronegativity

Answer 39

indication of attractive force which an atom exerts on shared e- pair

measured on scale of 0-4

Question 40

density of metals trend

Answer 40

from left to right across a period , atomic radius decreases while atomic mass increases
thus density of metal increases

top to bottom in a group: atomic radius increases, mass of atoms increases resulting in increase in density

Question 41

melting and boiling point trends

Answer 41

moving left to right across period  for groups 1-14
melting+boiling increase
mp+bp of groups 15-18 v low
top to bottom in groups 1+2, decrease
top to bottom groups 17+18, increase