Electron arrangement and ionisation energies Flashcards
Define isotopes
Atoms of the same element containing the same number of protons but different number of neutrons
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
Define relative atomic mass
The average mass of an atom of an element compared to 1/12th of the mass of an atom of carbon-12
How many electrons can shell 1,2,3 and 4 hold up to
shell 1 = 2
shell 2 = 8
shell 3 = 18
shell 4 = 32
Define an atomic orbital
A region within an atom that can hold up to 2 electrons with opposite spins
What is the shape of the s orbital called
sphere
What is the shape of the p orbital called
dumbbell
Define first ionisation energy
The energy required to remove one mole of electrons from one mole of a gaseous atom
What is the general trend in first ionisation energies across a period
. First ionisation energy increases across a period
. There are more protons in the nucleus
.But the outer electrons are in the same shell
.Increase in nuclear attraction from the outer electron
.Decrease in atomic radius
.So more energy is requied to remove the electron
What is the general trend in first ionisation energies down a period
. More shells
. More shielding
. The number of protons increase but this is far outweighed by the increase in shielding
. Nuclear attraction decrease
. Atomic radius increases
. Less energy required to remove outermost electron
Define successive ionisation enrgy
Successive ionisation energy are a measure of the energy required to remove each electron in turn from an atom
What is the general trend of successive ionisation energies
. Number of protons remain the same but proton to electron ration is increasing
. So more nuclear attraction on remaining electrons
