The Atomic Structure Flashcards
What are some examples of isoelectric elements/ions?
N(3-) O(2-) F(-) Ne Na+ Al(3+) Mg(2+)
What happens when transition metals form ions?
they always lose the 4s energy levels before the 3d energy level
What is ionisation energy?
Ionisation energy is the amount of energy required to remove 1 mole of electrons from a mole of atoms in the gaseous state and is measured in kJmol(-1)
What happens to the ionisation energy the further away the outer orbital is from the nucleus?
The ionisation energy decreases as there is weaker force of attraction, so it is easier to remove the electron from the outer shell.
Why does group 4 only bond covalently?
Group 4 atoms can either lose or gain 4 electrons as they already have the outer shell half-full.
they bond covalently to share electrons
What are the 3 factors that affect ionisation energy?
- Distance from the nucleus
- Shielding
- Nuclear charge
How does distance affect ionisation energy(I.E)?
- The further away the orbital is, from the nucleus
- The weaker the force of attraction
- The lower the I.E needed
How does shielding affect the I.E needed?
- as the number of electrons between the nucleus and the outer electrons increases
- The weaker the force of attraction to the nucleus
- The lower the I.E needed
How does nuclear charge affect the I.E needed?
- The more protons there are than the electrons
- The more positively charged the nucleus
- The stronger the force of attraction
- The higher the I.E needed
What happens to the ionisation energy when in the same block?
e.g. p-block, s-block e.t.c
- The higher the number of protons
- They are in the same sub-shell
- The stronger the force of attraction
- The higher the amount of I.E needed
What happens to the ionisation energy when jumping blocks?
e.g. s-block to p-block
- There is a new sub-shell (further away from the nucleus)
- The weaker force of attraction
- The lower the I.E needed
When happens to the ionisation energy during electron-pair repulsion?
- The electrons are already repelling each other
- They are easier to remove
- The lower the I.E needed
Why do you need more I.E to remove an electron from an ion?
- There are more protons than there are electrons
- The ion is positively charged
- There is a stronger force of attraction
- More I.E is needed
What is successive ionisation energy?
Successive ionisation energy is the energy needed to remove 1 electron from each ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions
How does successive ionisation energy help you determine which group an element is in?
The largest jump between 2 ionisation energies tells you which group the element belongs to.
If the largest jump in ionisation energy is between the first and the second ionisation energies, then the element is in group 1.
What is the trend in the first ionisation energies down a group in the periodic table?
The first ionisation energies decrease.
What is the trend in the first ionisation energies across a period in the periodic table?
The first ionisation energies generally increase.
What is the principal quantum number?
The principal quantum number is the relative overall energy of each orbital and the energy increases as the distance from the nucleus increases.
What is the maximum number of electrons that the first to the fourth shells can contain?
Shell 1 - 2
Shell 2 - 8
Shell 3 - 18
Shell 4 - 32
What is the relative mass and charge of a proton?
Relative mass - 1
Relative charge - +1
What is the relative mass and charge of an electron?
Relative mass - 1/2000
Relative charge -> -1
What is the relative mass and charge of a neutron?
Relative mass - 1
Relative charge - 0
Which subatomic particles decide the chemical properties of an element?
The number and arrangement of electrons
Why do physical properties of isotopes of an element differ?
Physical properties are dependant on the mass of the atom.
Where is most of the mass of an atom found?
In the nucleus
What can be found in the nucleus?
Protons and neutrons
What can mass spectrometry be used for?
- To identify elements
- To identify molecules
What is the electronic configuration of copper?
1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 4s(1) 3d(10)
What is the electronic configuration of chromium?
1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 4s(1) 3d(5)
Why do chromium and copper donate one of the 4s electrons to the 3d sub-shell?
- They become more stable
- Chromium has a full outer shell
- Copper has half of the outer shell full
What happens to the I.E between group 2 and 3?
The I.E drops due to the sub-shell structure
What happens to the I.E between group 5 and 6?
The I.E dops due to electron repulsion
Why does the successive I.E increase with each shell?
- Electrons are being removed from an increasingly positive ion
- There is less repulsion between remaining electrons
- Remaining electrons are held more strongly by the nucleus
What do big jumps in I.E show?
It shows an electron is being removed from a new sub-shell closer to the nucleus
How did John Dalton describe atoms as?
He described atoms as solid spheres and different elements are made up of different spheres
What did J.J Thomson discover in 1897?
The electron
The plum pudding model was created
Which famous experiment in 1909 did Ernest Rutherford and his students Hans Geiger and Ernest Marsden conduct?
They fired alpha particles at a thin gold foil
What did the gold foil experiment show?
Most of the particles passed straight through the gold with very few being deflected backwards
What did Rutherford conclude from the experiment?
- The plum pudding model couldn’t be right and he developed the nuclear model
- The atom contained a tiny positively charged nucleus and surrounded by electrons
- Most of the atom was empty space
What did Niels Bohr propose about the model of the atom?
Electrons exist in shells or orbitals
What happens when electrons move between shells?
Electromagnetic radiation(fixed energy or frequency) is emitted or absorbed
Why did the Bohr model replace the nuclear model?
The Bohr model fitted experimental observations of radiation emitted and absorbed by atoms
What did scientists discover which meant that the Bohr model wasn’t quite right?
Scientists discovered not all electrons in a shell have the same energy
-They discovered sub-shells
Why is the Bohr model of the atom still useful today?
- It is simple
- It explains many experimental observations like bonding and ionisation energy trends
