Chapter 7 Flashcards
What are elements arranged by?
In order of increasing atomic (proton) number
Where are the s-blocks?
Group 1 and 2.
Where are the d-blocks?
Middle of elements.
Where are the p-block elements?
On the right hand side of periodic table.
What do elements in the same group have?
Have the same number of outer electron shells and similar chemical properties.
What do elements in the same period have?
Have the same number of electron shells.
What are rows in the periodic table called?
Periods.
What are columns in the periodic table called?
Groups.
What is periodicity mean?
Is the repeating trends in the physical and chemical properties of the elements along periods.
What are the sub-shells in Period 2?
2s- 2p
What are the sub-shells in Period 3?
3s - 3p - 3d
What is first ionisation energy?
Is the energy required to remove one mole of electrons from one atoms in the gaseous state.
General equation for first ionisation energy?
X(g) to X+(g) + e-
What is successive ionisation energy?
Is the removal of more than 1 electron from the same atom.
General equation for successive ionisation energies?
X(n)+(g) to X(n+1)+(g) + e-
Why happens to first ionisation energies down a group? why?
It decreases down a group: the no. of shells increases, which increases atomic radius and shielding. Attraction between the nucleus and other electrons decreases despite an overall increase in nuclear charge.
Why happens to first ionisation energies down a period? why?
It increases across a period. As the nuclear charge increases but with a similar amount of shielding. This means there is a decrease in atomic radius. Attraction between the nucleus and outer electrons increases.
Why does Na have a lower first ionisation than Neon?
As Na will have the it’s outer electron in the 3s sub-shell which is further from the nucleus and more shielded, so Na’s outer electron is easier to remove + has a lower ionisation energy.
Why is there a drop in ionisation energy between Mg and Al?
Because Al is starting to fill out a full 3P sub-shell, whereas Mg has it’s outer electron in the 3s sub-shell. The electron in the 3P subshell are slightly easier to remove because the 3P electrons are higher in energy and slightly shielded by the 3s electrons.
Why is there a drop in ionisation energy between P and S?
In sulfur, the 4 electrons in the 3p level, are all paired. While in phosphorus there are 2 paired electrons and 1 lone electron in the 3p level. Due to the electron repulsion of the paired electrons in sulfur, less energy is required to remove 1 mole of electrons from its sub-level, as there is less of an attraction of these electrons towards its nucleus. Therefore, the first ionisation energy for sulfur will be slightly lower than that of phosphorus, due to the paired electrons in its 3p sub-level.
What it is metallic bonding?
Is it the strong electrostatic attraction between delocalised electrons and cations, the positive ions.
What is giant metallic bonding?
It is the regular arrangements of cations in all metals.
What are the three giant covalent lattices?
- Diamond
- Graphite
- Graphene
What are the physical properties of giant metallic lattices?
- good conductor of heat - free moving electrons in the lattice
- melting & boiling points are usually quite high due to strong attraction
- malleability & ductility - delocalised electrons protect cations from repelling
- metals do not dissolve in, rather they react in water
