Atomic structure Flashcards
what are the relative masses of protons, neutrons and electrons ?
Proton: 1
Neutron: 1
Electron: 0.0005
What does the atomic number represent ?
Number of protons
What does the mass number represent ?
Number of protons - number of neutrons
How do you find the number of electrons in an element ?
Same as the proton/atomic number
What is the mass number an average of ?
All of the elements isotopes
Isotopes have the same number of …. but a different number of ….
Same: protons
Different: neutrons
Due to the different isotopes having the same number of ….. they all possess the same ….. and ….. properties
- electrons
- chemical
- physical
Electrons are arranged in ….. or …… which have …. or ……
Electron shells
Energy levels
Sub-shells
Sun-levels
Each sub-level consists of …. …..
Electron orbitals
What is an electron orbital ?
A region of space in which the electron spends most of its time/ is most likely to be in
Each …… can hold ……. with ….. ….
Orbital
2 electrons
Opposite spins
Electrons will always fill the ….. ….. ….. first
Lowest energy level
Why does 4s fill before 3d ?
Because 4s is at a lower energy level
What is the order of orbital filling ?
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p etc
The ….. up the energy levels the …. ….. the electrons have
Higher
More energy
Electrons will always enter the ………… available
Lowest energy orbital
Electrons prefer to occupy …… on their …… and only ………. … when no …… orbitals of the ….. ….. are available
Orbitals Own Pair up Empty Same energy
In ….. the electrons in the …… energy level are …. ….
Ions
Highest
Lost first
Electrons are ….. from … before ….
Lost
4s
3d
…… for how electrons are …… in ….. comes from ……. …..
Evidence
Arranged
Atoms
Ionisation energies
The ….. …… ….. is the …… required to remove ….. …. from each …… in a …… of …….. atoms producing one mole of … …… …….
1st ionisation energy Energy One electron Atom Mole Gaseous 1+ gaseous ions
The ….. …… ….. is the energy required to remove the …… ….. not ….. …..
2nd ionisation energy
Second electron
Both electrons
What three factors affect ionisation energy ?
Distance from the nucleus
Nuclear charge
Shielding
What affect does the distance from the nucleus have on ionisation energy ?
The greater the distance the less the attraction between the nucleus and outer electron
What affect does nuclear charge have on ionisation energy ?
The more protons the nucleus has the higher the nuclear charge the higher the attraction between the nucleus and outer electron
What affect does shielding have on ionisation energy ?
The greater the shielding I.e. the more energy levels there are the weaker the attraction between the nucleus and outer electrons
