topic 1 Flashcards
Define isotope
Elements with the same number of protons but different number of neutrons
Define relative atomic mass
The weighted mean mass of an atom of an element, compared to 1/12th mass of an atom of carbon 12
Define relative isotopic mass
The mass of an atom of an isotope, compared to 1/12th of the mass of an atom of carbon 12
What must your abundance add up to?
100%
Formula for relative atomic mass
(Abundance A x m/z of A) + (Abundance B x m/z of B) all over total abundance
How do you calculate isotopic mass?
Do relative atomic mass and then solve for x
Why are arrows in electronic figuration in different directions?
Spin pairing. When 2 electrons occupy one orbital, they ‘spin’ in opposite directions
Why do you full orbitals singly first then pair them up?
Electron repulsion
Why would a transition metal with an electronic configuration of 3d5 4s2 form a unipositive cation with an electronic configuration of 3d5 4s1 and not 3d4 and 4s2?
Lose from the 4s orbital first then from 3d as 4s higher energy when filled but lower energy when empty.
What is n=1 in the atomic emission spectra?
Ground state
Why are line spectra used?
to identify atoms and molecules.
What is a series in atomic emission spectra?
A group of lines
Why do lines in atomic emission spectra get closer together?
The energy and frequency increases
What does the line spectrum show?
The frequency of light in coloured bands
Where must an electron fall to for a line to be produced at uv?
Ground state, n=1
Where must an electron fall for a line to appear at visible light in atomic emission spectra
N=2
Where will the line in atomic emission spectra appear if n=3?
Infrared
Define first ionisation energy
The minimum amount of energy required to remove 1mol of electrons from 1mol of atoms in the gaseous state to form one mole of unipositive gaseous cations
Ionisation energy trends down a group
Decreases down groups. Atomic radius increases. Outer electrons are further from nucleus, so there is a weaker attractive force, therefore less energy is required. Shielding increases so less energy is required to remove electrons.
What is successive ionisation
The removal of more than 1 electron from the same atom
What is the general trend of successive ionisation
There is a general increases in energy as removing electrons causes the atom to become increasingly more positive
What happens to the atomic radius across period 3?
It decreases. There is an increased nuclear charge because there is an increase in protons
What happens to the atomic radius down a group?
Increases due to extra electron shells being added
What is the trend of ionisation energies across periods
Increases due to increasing number of protons and nuclear attraction increases. Shielding is similar and distance marginally decreases. More energy is required to remove outer electrons.
