M3 - Periodicity, Groups 2 and 7 Flashcards
C
Are halogens oxidising or reducing agents?
Oxidising agents, as they themselves are reduced (electron acceptors)
A
Why are giant covalent lattices insoluble?
Covalent bonds holding it together are too strong to be broken by interaction with solvents.
What are the properties of giant covalent lattices?
High melting and boiling points
Insoluble in almost all solvents
Do not conduct (except for graphite and graphene)
formed from carbon, silicon anf boron
How were the elements ordered by Mendeleev?
Increasing atomic mass
B
what is produced when Ba is added to water?
Barium hydroxide and hydrogen gas
what is the colour of iodine in an organic solvent?
Purple
What is the name for the horizontal rows of the periodic table?
Periods
Define First Ionisation Energy (2)
The energy required to remove one electron from each atom (1) in one mole of gaseous atoms to form one mole of gaseous 1+ ions (1)
What causes the large jumps in successive ionisation energies?
Moving down to a closer shell, as these electrons are closer so experience a greater nuclear attraction.
What block is Lithium placed in and why?
Li is an S-block element - A s-block element has its highest energy/outermost electron in a s subshell/orbital
What is ionisation?
The removal of one or more electrons from an atom.
Which is the most reactive halogen and why?
Fluorine, as it has a small atomic radius and less shielding. Easier for fluorine to gain a electron
Why does ionisation energy increase across a period?
The number of protons in the nucleus increases so nuclear charge increases causing atomic radius to decrease, whilst shielding stays the same.
Complete the word equation;
HEAT
Calcium carbonate ->
Calcium oxide and carbon dioxide
How does electron shielding affect ionisation energy?
Inner shell electrons repel outer shell electrons, called shielding. This reduces the attraction between the nucleus and the outer electrons. therefore lower ionisation energy
In period 2, explain the fall of ionisation energy from nitrogen to oxygen
Nitrogen’s electrons in the 2p sub shell are unpaired so oxygen’s 8th electron is paired, causing repulsion and a lower ionisation energy.
what is the colour of aqueous chlorine?
Pale green
Why do most giant covalent lattices not conduct electricity?
All four outer shell electrons are involved in covalent bonding. No mobile charge carriers.
How does atomic radius affect ionisation energy?
Greater distance between the nucleus and outer electrons, the attraction is lower.