Karteikarten
Topic 1: Atomic Structure and Periodic Table
Karten in diesem Stapel (13)
- 1IsotopeAtoms with the same number of protons but different number of neutrons
- 2Relative Isotopic MassMass of one atom on an isotope compared to 1/12th of the mass of Carbon-12
- 3Relative atomic massAverage mass of one atom compared to 1/12th of the mass of one atom of carbon-12
- 4Relative molecular massAverage mass of a molecule compared to 1/12th of the mass of one atom of carbon-12
- 5How to work out relative atomic massSum (isotopic mass x % abundance) / 100
OR
Sum (isotopic mass x relative abundance)/ total relative abundance - 6Uses of Mass spectrometersDrug testing in sport
Quality control in pharmaceutical companies
Radioactive dating to determine fossil ages - 71st Ionisation energyThe energy required when 1 mol of gaseous atoms forms 1 mol of gaseous ions with a +1 charge
H(g) -> H+ (g) + e- - 82nd Ionisation energyThe energy required when 1 mol of gaseous atoms forms 1 mol of gaseous ions with a +2 charge
H(g) -> H 2+ (g) + e- - 9Factors that affect ionisation energy1. Attraction of the nucleus
- More protons = greater attraction
2. Distance of the electrons from nucleus
- Bigger atoms = further outer electrons = weaker attraction to nucleus
3. Shielding of the attraction to nucleus
- More inner shells = weaker attraction of the nucleus - 10PeriodicityRepeating pattern/trend across a period
- 11Trends in atomic radiusDecrease as you move from left to right across a period
- more protons = more +ve charge attraction for electrons in the same shell with similar shielding - 12Trends in 1st I.EGeneral increasing trend (increasing no. of protons)
** Drop between Mg and Al: Al begins to fill in 3p subshell, electron is easier to remove as 3p electrons are higher in energy
** Drop between P and S: S second electron added to the same 3p orbital = repulsion between electrons - 13Melting and boiling points1. Na, Mg, Al - Metallic bonding: strong bonding between increasing no. of electrons
2. Si - Macromolecular: strong covalent bonds need high energy to break
3. Cl2, S8, P4 - Simple molecular: weak London forces, little energy needed to break
4. Ar - Monoatomic: weak London forces between atoms