Atomic Structure MA, SI Flashcards
State the meaning of the term isotopes
An element which contains the same number of protons and electrons but a different number of neutrons.
Give the relative mass and charge of an electron
relative mass: 1/1840
relative charge: -1
Define the term ‘first ionisation energy’
Energy required to remove one mole of electrons from one mole of atoms in a gaseous state (kJ mol -1)
Name the 4 stages of mass spectrometery
1) Ionisation
2) Acceleration
3) Deflection
4) Detection
Write an equation to demonstrate the first ionisation energy of Sodium (Na)
Na (g) –> Na+ (g) + e-
State the definition of ‘relative atomic mass.’
The average mass of an atom of an element compared to 1/12 the mass of an atom of Carbon-12.
State the definition of ‘relative molecular mass.’
The average mass of a molecule compared to 1/12 the mass of an atom of Carbon-12.
What are the three factors affecting Ionisation Energy?
Nuclear charge, distance from the nucleus and shielding.
“The first ionisation energies of elements down a group of the periodic table decrease.”
True or false?
True.
As you move across a period, what is the trend of ionisation energies?
It increases, this is because the number of protons have also increased so there is a stronger nuclear attraction.
Describe the ‘acceleration’ aspect of a mass spectrometer.
Positive ions are accelerated by an electric field. Those with a lower mass/charge ratio experience a greater acceleration.
What are electron shells made up of?
Sub-shells and orbitals.
How do electrons fill orbitals?
Singly and then they double up.
Why do some ions travel at higher speeds during mass spectrometry?
Because they have a lower mass and high charge, a lower mass/charge ratio.
State the relative mass and charge of a neutron
Relative mass: 1
Relative charge: 0
