Unit 1 Topic 1 PT and Trends

Question 1

What is an atom

Answer 1

An atom is the smallest unit of matter and they are composed of three subatomic particles

Question 2

Outline the 3 subatomic particles, their charges, masses and locations

Answer 2

Proton
- positively charged
- 1
-found in the nucleus

Neutron
- neutral charge
- 1
- found in the nucleus

Electron
- negatively charged
- 1/1800
- found in the shells that surround the nucleus that are held by electrostatic attraction

Question 3

What is an ion

Answer 3

Ions are atoms that have lost or gained electrons and therefore result in an unbalanced charge that is either positve or negative

Question 4

Cation

Answer 4

Cations are positive ions that have lost an electron meaning there is more protons than electrons and therefore a positive charge

Question 5

Anions

Answer 5

Anions are negative ions that have gained an electron meaning there is more electrons than protons and therefore a negative charge

Question 6

What are Features of the periodic Table

Answer 6

-Each row is called a period and outline how many shells will make up the electron configurations in the said atom
-A column is known as a group and dictates the number of valence electrons that will be present in the electron configuration

Question 7

What does the Bohr Model propose

Answer 7

• proposes that electrons reside in shells
• such shells are arranged that each shell gets progressively further away from the nucleus than the previous
• The number of electrons present in each shell is dictated by the rule 2n^2
• proves that the atom is mostly empty space with a positive charge near the centre as concluded by the rutherford gold foil experiment

Question 8

What are the subshells for electronic configuration and where are they located on the periodic table

Answer 8

S- groups 1 and 2
P- groups 13-18
D- groups 3-12

Question 9

Orbital

Answer 9

The physical regions occupied by the electrons
- max number of two electrons per orbital
- the orbitals and subshells are filled in increasing energy levels

Question 9

What happens when electrons are heated

Answer 9

-Electrons when exposed to heat gain energy
-This causes atoms to be in a state known as the excited state
-This is where the atoms is very volatile and spontaneous
-The electrons in the atoms electron configuration will jump to higher energy levels as the electrons have absorbed energy from the heat
-The electrons that have been excited will then drop to ground state releasing the energy they have absorbed as a form of electromagnetic radiation present in the form of light

Question 10

Electronic configuration of copper

Answer 10

1s2 2s2 2p6 3s2 3p6 3d10 4s1

Question 11

Electronic Configuration of chromium

Answer 11

1s2 2s2 2p6 3s2 3p6 3d5 4s1

Question 12

Electron Configuration of Krypton

Answer 12

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6

Question 13

Discuss the energy levels in the 3rd and 4th energy levels

Answer 13

The 4s subshell is of lower energy than the 3d subshell. Thereofre for elements past calcium fill 3p6, leave a gap, write 4s2 and then come back and place electrons in the 3d subshell

Question 14

Define Core charge

Answer 14

Core charge is the attraction of valence electrons have to the nucleus as opposite charges attract
- it is equal to the number of valence electrons in an atom

Question 15

Trends of Core charge

Answer 15

Increases across a period due to the nucleus being more positive, meaning the valence electrons is more strongly attracted to the nucelus

Remains the same down a group as number of valence electrons remains the same

Question 16

Define shielding effect

Answer 16

Refers to how great of a shield the valence electrons have from the nucleus
- is equal to the number of inner shell electrons

Question 17

trends of shielding effect

Answer 17

Across a period shielding effect is constant as there is no new shell with electrons that is added but the nucleus becomes more positive and therefore the valence electrons are more strongly attracted to the nucleus

Down a group shielding effect increases as number of inner shells increases and therefore the valence electrons are less strongly attracted to the nucleus as they are further away

Question 18

Atomic Radius

Answer 18

Distance between the nucleus and the valence electrons

Question 19

Trends of Atomic radius

Answer 19

Across a period as the core charge increases and shielding effect is kept constant therefore the valence electrons are more strongly attracted to the nucleus hence decreasing the atomic radius

Down a group atomic radius increases as there is an increased number of occupied electron shells

Question 20

Electronegativity

Answer 20

The ability of an atom to attract other atom’s valence electroms to itself

Question 21

Trends of Electronegativity

Answer 21

Across a period core charge increases with a constant shielding effect and therefore the nucleus is more attracted to any valence electrons and thus higher electronegativity

Down a group electronegativity decreases as valence electrons are less strongly attracted to the nucleus as they are further away as the atomic radius increases and an increased shielding effecr

Question 22

First ionisation energy

Answer 22

the energy required to remove one electron from valence shell in a gaseous atom

Question 23

Trends of first ionisation energy

Answer 23

Across a period first ionisation energy increases as core charge increases, therefore the valence electrons are more strongly attracted to the nucleus so they require more energy to remove

Down a group first ionisation energy decreases as the valence electrons are less attracted to the nucleus, therefore it is easier to remove as the valence shell is further from the nucleus meaning there is a greater shielding effect on the valence electrons

Question 24

metallic character and Non- metallic character

Answer 24

How easily or not an atom will release its valence electrons