Atomic structure+ first ionjisation energies

what happens when we move further away from the nucleus

energy of shells increases

whats the maximum electrons the first shell can hold

2

whats the maximum electrons the second shell can hold

8

whats the maximum electrons the third shell can hold

18

whats the maximum electrons the fourth shell can hold

32

where are electrons found in shells

regions called atomic orbitals

atomic orbital definitions

region around nucleus that can hold up to two electrons with opposite spins

what do we need to know about spins

-electrons either have up or down spins

-when electrons in the same orbital they must have opposite spins

what is a electron considered to be

a cloud of negative charge that has the same shape as the orbital occupied by the electron

whats the exact location of am electron

-scientist can never be certain of the exact location of an electron

-orbital shows us 95% probability of where electrons exist

typoes of atomic orbitals

s,p,d,f

whats the maximum no of electrons a single orbital can hold

2 electrons

whats a subshell

all the same type of orbitals in the same shell

what happens to the energy of the subshell as we move away from from the nucleus

increases

rules for filling out atomic orbitals

-orbitals with lowest energy= filled first

-up to two electrons in orbital (must have opposite spins)

-if orbitals have same energy then elements are put in individual orbitals before being paired

when do electrons in the same orbital do

repell

what gets filled first 3d subshell or 4s

4s

do electrons prefer to be in seperate boxes or the same one

if enough space seperate

what are the exceptions in the electron configaration rules

chromium + copper

what is the exception being made when it comes to chromium+copper

4s subshell contains only one electron even though there are electrons in the subshell

why does chromium have a incomplete 4s subshell while having electrons in the 3d subshell

by having 1 electron in the 4s subshell it can have a half full 3d subshell which is more stable

why does copper have a incomplete 4s subshell while having electrons in the 3d subshell

by having 1 electron in the 4s subshell it can have a full 3d subshell which is more stable

in what order do elements loose electrons

4s subshell befor 3d

first ionisation energy definition

the energy needed to remove one mole of electrons from one mole of atoms in theire gaseous state to form one mole of 1+ ions (gaseous state)

second ionisation energy definition

-energy needed to remove one mole of electrons from one mole of 1+ ions in their gaseous state to form one mole of 2 + ions (gaseous state)

what are the electrons in a atom attracted too

the protons in the nucleus

what are the factors that affect ionisation energy

• atomic ratius - distance between nucleus and outermost electrons

• atomic charge - the number of protons- the more the greater the charge

• shielding- no of electron shells

if the attraction between outer electrons and nucleus is greater what will happen to the ionisation energy

-ionisation energy will be greater

if the atomic radius is greater will there be more or less ionisation energy required

less

if the atomic charge is greater will there be more or less ionisation energy required

more

if the shielding is greater will there be more or less ionisation energy required

less

what happens each time we remove a outer electron

-remaining electrons in outershell are pulled slightly closer to nucleus

what does electrons being pulled slightly closer to nucleus mean for ionisation energy

-there will be a greater attraction between outer electrons

-which causes ionisation energy to gradually increase

what happens to first ionisation energy as we go down a group

it decreases

what are the two factors of why first ionisation energy decreases as we go down groups

-as we go down atomic radius increases= outer electron shell further from nucleus

--no of internal energy levels increase = more shielding

-both decrease attraction between nucleus and outer electrons

what happens to first ionisation energy as we go down a period

-usually increases(some exceptions)

why does first ionisation energy usually increase as we go down in a period

-no of protons increases=increases attraction between the nucleus and electrons

-that causes atomic radius to decrease across a period

-both= outer electrons more attracted to the nucleus