atomic structure, mass spec, electron configurations and orbitals

Atomic Structure and the Periodic Table

atomic number

the number of protons in an element. this detremines the type of element it is

mass number

the amount of proton and neutrons in an element

isotopes

a different version of an element which has the same number of protons but different number of neutrons (diff mass number)

relative isotopic mass

(basically the mass number of an isotope) the mass of an atom of an isotope compared to 1/12 of the mass of a carbon-12 atom

relative atomic mass

the weighted mean mass of an atom of the element compared to 1/12 of the mass of a carbon-12 atom

relative formula mass

Relative formula mass is the total sum of the relative atomic masses of all the atoms in a chemical formula

relative molecular mass

the total sum of the relative atomic masses of all the atoms present in a molecule

relative isotopic mass

The mass of an atom of an isotope of the element compared to 1/12 of the mass of an atom of carbon 12

what is a mass spectrometer

1. measures the masses of atoms and molecules

2. Produces positive ions that are deflected by a magnetic field according to their mass to charge ratio (m/z)

3. calculate the relative abundance of each positive ion and displayed this as a percentage

4. Positive ions could be positively charged at atoms positively charged molecules or positively charged fragments of

what is the molecular ion peak?

The peak with the highest M/Z ratio in the mass spectrum, The M peak

quantum shells

• The energy level of an electron

• Elections can only exist in certain well defined energy levels

do electrons in the first quantum shell have the lowest energy for the element or the highest and explain why

electrons in the first quantum shell have the lowest energy for that element because the first quantum show is located in the region closest to the nucleus therefore it experiences a greater force of attraction between the positive nucleus and the negative electrons on the shells

name the four types of subshells

S,P,D and F

what are orbitals

A region within an atom that can hold up to 2 electrons with opposite spins

what do each subshells contain?

orbitals

how many orbitals do each subshells contain

S - 1

P - 3

D - 5

F - 7

how many electrons can each orbital have

2 electrons

how to calculate The number of electrons that can exist in each subshell

multiply the number of orbitals in each subshell by two (Which is the number of electrons that each orbital can have)

what is hunds rule

electrons will occupy the orbital singly before pairing takes place due to electron Repulsion

what is Pauli Exclusion principle

two electrons cannot occupy the same orbital unless they have opposite. Election spin is usually shown by the use of upward and downward arrows