Structure 1 Flashcards
Homogeneous Mixture.
- Components in same phase
- Even distribution of particles
Heterogeneous Mixture
- Components in different phases
- Uneven distribution of particles
Pure Substance
- Elements
- Compounds
(Chemically bonded)
Mixtures
- Homo/hetero-geneous
(Physically bonded)
Kinetic Molecular Theory
- All matter made up of constantly moving particles
- Energy of particles proportional to temperature
- Change in energy can drive change in state
- Empty space between particles increase from solid —> gas
- Attractive forces between particles increase as particles move closer
Relative Atomic Mass
Weighted average mass of an atom compared to 1/12th the mass of Carbon-12
—> ∑(%abundance x isotopic mass)/100
Mass Spectrometry (HL)
Measuring the individual masses of atoms in an element.
1) Vaporization
2) Ionization - electrons fired at sample, particles made into +1 charge
3) Acceleration - electric field
4) Deflection - magnetic field (effect by mass, results in change in velocity)
5) Detection - can detect the number of isotopes depending on the speeds of particles
Aufbau Principle
Lowest energy levels filled first.
—> Exceptions: |Cr| & |Cu|
—> Half filled (Cr)/full (Cu) sublevels are more stable than partially filled ones.
—> Exception occurs due to very small energy diff. Between 3d & 4s sub-levels.
Hydrogen Emission Spectra (HL)
1) …—> n=1 (Lyman Series - UV)
2)…—> n=2 (Balmer Series - Visible Light)
3)…—> n=3 (Paschen Series - Infrared)
Convergence Limit
Energy levels move closer together as they are further away from the nucleus. Eventually they converge and no extra energy is needed to promote an electron so it becomes ionized.
—> You can calculate the First IE using the frequency of the convergence limit (E = hf)
Hund’s Rule
Orbitals within same level filled first/no empty space.
Pauli’s Exclusion Principle
Positive & negative spin of electrons in orbitals.
Ionization Energy
The energy required to remove one mole of electrons from one mole of gaseous atoms.
—> General trend: increase across period, decrease down group
—> Exceptions: Slight drop between sublevels (eg. p having slightly higher energy which counteracts increase in Zeff)
Ground State
The lowest energy level occupied by an electron in an atom.
Empirical Formula
Simplest whole number ratio of atoms in a compound.
