Chemistry Models of particulate nature

How do electrons return to lower levels?

by releasing energy

How do we refer to electrons which are at a higher energy and farther from the nucleus?

in an excited state

what do the lines in line emission spectra represent?

a specific energy value suggesting that electrons can only possess a limited choice of allowed energies

what is it called when lines move towards eachother in the line emission spectra?

convergence

what does the an electron reaching maximum amount of energy mean ( last lines on line emission spectra)

electron reaches ionisation energy

Transition from n = ∞ to n = 3

infared region with low energy

Transition from n = ∞ to n = 2

visible region with medium energy

Transition from n = ∞ to n = 1

ultraviolet region with high energy

emission spectra rule to remeber

always has to be emission, meaning to goes downwards

What is ionisation energy?

minimum energy needed to remove one mole of electrons from one mole of gaseous atoms in their ground state

What is the Aufbau principle?

Electrons ‌occupy the lowest available ‌energy level first

what happens to electrons in an atom when they absorb energy?

reach an excited state moving from a lower to higher energy level, energy is absorbed to overcome attraction to the nucleus

what does it mean if an electron configuration ends in d?

it is a metal

what does it mean if an electron configuration ends in s?

usually a reactive metal (except for hydrogen)

what does it mean when an electron configuration ends in p?

likely a non metal

how can we deduce group number from electron configurations?

add the last two s and p orbitals together and add 10

how can we deduce period number from electron configurations?

look at the number of the last orbital

how can we deduce ionisation from electron configurations?

ionisation decreases down a group, if in same group look for full orbitals which mean higher ionisation energy

What electron configuration does He

what are isotopes?

atoms with the same number of protons and different number of neutrons

why do isotopes have the same chemical properties?

chemical properties are determined by electron configurations which is the same in isotopes

why do isotopes have different physical properties ?

physical properties are determined by the mass of the atom, which is different due to difference in neutrons