Module 3 P1 Flashcards
How are the elements arranged in the periodic table?
- In order of increasing atomic number
- in periods
- in groups
How were elements arranged in Mendeleev’s original periodic table?
In order of increasing atomic mass
What do periods show in the periodic table?
Repeating trends in physical and chemical properties.
Elements in the same period have the same number of shells
What is periodicity?
The repeating pattern seem across different periods
What do groups show in the periodic table?
Elements with similar chemical properties because elements in the same group have the same number of electrons in their outer shell
What is an advantage of numbering the groups in the periodic table as 1-7 + 0 rather than 1-18?
The group number matched the number of electrons in the highest energy shell
What is a disadvantage of numbering the groups in the periodic table as 1-7 + 0 rather than 1-18?
Doesn’t include the d block
What is an advantage of numbering the groups in the periodic table as 1–18 rather than 1-7 + 0?
The numbers each column in the s, p and d blocks sequentially
Which groups are in the s block in the periodic table?
Groups 1 and 2 plus hydrogen and helium
Which groups are in the p block in the periodic table?
Groups 13 to 18
Why are group 18 elements inert?
Their sub shells are filled
Which groups in the p block can share electrons to form covalent bonds?
Groups 14-17
Which groups in the p block are capable of gaining electrons to form negative ions?
Groups 16 and 17
Key points about ionisation energies:
- endothermic
- always use the gas state symbol
- the lower the ionisation energy, the easier it is to form an ion
- measured in KJmol^-1
Which factors affect an element’s ionisation energy?
- atomic radius
- nuclear charge
- shielding
How do successive ionisation energies show shell structure?
A large increase/ jump in the ionisation energy required indicates that the electron is in a new shell/energy level.
What do the peaks and troughs on ionisation energy graphs show?
Evidence of sub-shells
What is another name for shell?
Energy level - the principal quantum number (n)
What is an atomic orbital?
A region around the nucleus that can hold up to two electrons with opposite spins
What shape is an a orbital?
Spherical
How many s orbitals are there in each s sub-shell?
One
What is the shape of a p orbital?
Figure of 8/ dumb-bell shape
How many p orbitals is there in one p sub-shell?
3
How many d orbitals is there in one d sub-shell?
5
How many f orbitals is there in one f sub-shell?
7
What are the four types of electron orbitals?
s, p, d, f
How many electrons can fit in each orbital?
2
Give the order in which the orbitals fill up in an electron
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p
In box diagrams, why do all the boxes on an energy level fill up before electrons are paired in orbitals?
Electrons repel each other
Why must two electrons in an orbital have opposite spins?
To help counteract the repulsion between the negative charges
