Periodicity

Question 1

how is the elements in the periodic table arranged

Answer 1

i’m order of increasing atomic number

Question 2

what does the periodic table and the position of the elements allow chemists to do

Answer 2

make accurate predictions of physical properties and chemical behaviour for any element

Question 3

what are groups in the periodic table

Answer 3

• vertical columns of elements
• contain elements with similar chemical properties
• common number of electrons in the outer shell of the group of elements

Question 4

what are periods in the periodic table

Answer 4

• horizontal rows of elements
• arranged with increasing atomic number
• increasing number of electrons
• move from metallic to non metallic elements

Question 5

Bonding and Structure or first 20 elements

Answer 5

Metallic (Li, Be, Mg, Al, K, Ca)

Covalent Molecular (H2, N2, O2, F2, Cl2, P4, S8, C60)

Covalent Network (B, C(diamond + graphite), Si)

Monatomic (Noble Gases, Group 0)

Question 6

Covalent Radius meaning:

Answer 6

measure of the size of an atom that forms part of one covalent bond

Question 7

Covalent Radius down a group?

Answer 7

INCREASES

as more shells are added to the atom making it bigger, and therefore increasing the covalent radius

Question 8

Covalent Radius across a period?

Answer 8

DECREASES
as the electrons being added are being pulled closer to the middle by the increasing nuclear charge, making the atom smaller, therefore decreasing atomic radius

Question 9

First Ionisation Energy:

Answer 9

the energy required to remove the furthest electron from the nucleus/ most loosely held electron

Question 10

Second + Subsequent Energies:

Answer 10

the energy required to remove further electrons

Question 11

Ionisation Energy down a group?

Answer 11

DECREASES
as more shells are being added so the further down the group you get the further away the electron gets from the nucleus; as well as more shielding by the inner shells, meaning less energy is required to remove it

Question 12

Ionisation Energy across a period:

Answer 12

INCREASES
as the electrons are on the same energy shell but protons are being added to the nucleus, increasing the nuclear charge and pulling the electrons closer, meaning more energy is needed to remove them

Question 13

Electronegativity:

Answer 13

• the measure of attraction an atom has for electrons in a bond
• the ability of an atom to attract an electron to itself

Question 14

Electronegativity down a group?

Answer 14

DECREASES
due to an increase in the distance and the number of shielding shells between the nucleus and the electron, making the atom have a decreased attraction

Question 15

Electronegativity across a period?

Answer 15

INCREASES
due to the number of charges on the nucleus increase due to protons being added, making the atom have an increased attraction