3.1 & 2
No description yet. This curated deck is ready for daily study.
Card preview (24)
How is the periodic table arranged
By increasing atomic no. In periods showing repeating trends in physical and chemical properties In groups having similar chemical properties
First ionisation energy
Removal of 1 mole of electrons from each atom in 1 mole of gaseous atoms
Metallic bonding
Strong electrostatic attraction between cations and delocalised electrons
Solid giant covalent lattices
Networks of atoms bonded by strong covalent bonds
Atomic radii across a period
Decreases More attraction to nucleus Greater no. of protons
When is the ionisation energy higher
With a smaller radius (higher nuclear charge) Greater attraction More energy needed
How do inner quantum shells affect the IE
Inner quantum shells shield the electrons from the attractive force of the nucleus The more inner quantum shells The greater the shielding effect The lower the IE
When a molecule sublimates what bonds are broken
The intermolecular forces not the covalent bonds
Why is Mg harder than Na
No. of delocalised electrons Charge on cations Cations are smaller, so the charge density is even greater
Why is there an increase in mp and bp of metals from Gp 1 to Gp3
Increased strength of metallic bonding: The charge on the positive ion is greater More delocalised ions (1 in 1+ vs 3 in 3+) Smaller ions (greater charge density)
Properties of metals
Malleable Ductile High mp and bp Good electrical conductors
Solubility of giant ionic lattices
Ionic lattices dissolve in polar solvents like water Cations attract delta negative charges on the O molecule in H2O Anions attract delta positive charges on the H molecules in H2O
Solubility of simple molecular lattices
London forces can form between molecules and non-polar solvents (hexane), weakening the lattice
Group 2 characteristics
Fairly high melting and boiling points Low densities
Group 2 reactions
2 Mg (s) + O2 (g) —> 2MgO (s) Ca (s) + 2 H20 (l) —> Ca(OH)2 + H2
Second IE
X (g) —> X^+ (g) and e^- X^+ (g) —> X^2+ and e^-
Why does reactivity increase down Group 2
Further from nucleus More shielding 1st and 2nd IE decreases
Why does solubility and pH increase down a group
Mg(OH)2 —> Mg2+ and 2 OH- Dissociation causes more hydroxide ions to be released —> more alkaline solution
Down Group 7
No. of full shells increase Outermost electrons further from nucleus Atomic radius increases
Forces in Group 7 molecules
London forces More electrons = stronger London forces
What do halogens react to form
Halide ions
Are halogens reduced or oxidised
Reduced Oxidising agent
Why does reactivity decrease down Group 7
Nuclear charge increases down a group Atomic radius increases Shielding increases (outweighs nuclear atraction) Attraction between nucleus and electron decreases Halogen less readily accepts an electron
Do halide ions get oxidised or reduced
Oxidised