Flashcards in 2.1 Periodicity Deck (32)
What are electron shells really called?
What is the formula to work out the maximum number of electrons in an energy level?
What are the energy sub levels?
S P D
Are electrons divided equally between sub levels?
Why don’t we know where electrons are at all times?
They exhibit wave particle duality
What is an orbital?
A volume of space that can hold a maximum of 2 electrons
How many orbitals and maximum electrons does the sub level S have? Which groups?
Group 1 and 2
How many orbitals and maximum electrons does the sub level P have? Which groups?
How many orbitals and maximum electrons does the sub level D have? Which groups?
How does the electron configuration progress?
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p
What happens the more energy levels there are?
The further away from the nucleus the more energy they have
How can we shorten electron configurations?
Using the noble gases in square brackets
These indicate a full energy levels
What are the two abnormalities in electron configuration?
What is the correct configuration of Chromium? Why?
[Ar] 4s1 3d5
Chromiums outer shell is half full so it loses an electron out of the s group and gains one in the d group
What is the correct configuration of Copper? Why?
[Ar] 4s1 3d10
Coppers outer shell is full so it loses an electron out of the s group and gains one in the d group
What does each sub level contain?
Electron orbitals which are regions of space in which are electrons are likely to be found
How is the electron configuration of d block ions different?
When d block elements form ions they lose s group electrons rather than d group
How can we represent electrons within sub levels?
Using spin diagrams
What properties do electrons have to do with their positions?
They have a property called spin
It tells us how they occupy orbitals
What are the two rules with spin diagrams?
2 electrons in the same orbital cannot have the same spin state
(Up then down)
Electrons always go into unoccupied orbitals first
(Up, up, up then down, down, down)
(Remember: look for a free seat on the bus)
What is first ionisation energy?
The energy required to remove one mole of electrons from one mole of atoms in the gaseous state
Or energy to remove the outer electron
What must elements be in ionisation energy?
How do we remove an electron? What is ionisation energy measured in?
Heat energy is supplied to overcome the attraction of the electrons to the nucleus
How do you write the equations for ionisation energy?
X - any element
X(g) —> X(g)+ + e-
X(g)+ —> X(g)2+ + e-
X(g)2+ —> X(g)3+ + e-
What happens to ionisation energy within individual elements? Why?
By making the ion positively charged it is harder to remove the next electron as the ion want to hold on to the remaining electrons
It requires more energy to remove the next one
What is changing across a period?
More protons are added therefore the outermost electron has a stronger electrostatic force of attraction to the nucleus
What is significant about electrons added across a period?
They are added within the same principle energy level therefore aren’t further from the nucleus
They are actually closer as atomic radius decreases
Why for individual elements does the ionisation energy vastly increase between 3s1 and 2p6?
The sub level is closer to the nucleus so more energy is required to remove the electron due to a stronger attraction
What is the general pattern of first ionisation energy across period 2 or 3? Anomalies?
It generally increases across a period
Between 3s2 and 3p1
Then 3p3 and 3p4
They are slight decreases
What is the general trend of first ionisation down a group? Why?
Less energy is required as the increase in energy levels means the electrostatic force of attraction is weaker to the nucleus
Why is there a decrease in ionisation energy between Mg and Al across period 3?
Mg - 3s2
Al - 3p1
Aluminium’s outer most electron is slightly further away from the nucleus which shows it requires less energy
Despite having more protons