Unit 1 Flashcards
Distillation
Two liquids with different boiling points (eg. water and alcohol)
Evaporation
A liquid with a soluble solid (eg. salt water)
Chromatography
A mixture of colours (eg. Black ink)
Rf value in chromatography
Distance travelled by ink/distance travelled by water
Electron configuration
1s2
2s2
2p6
3s2
3p6
4s2
3d10
4p6
Hund’s Rule
- Every orbital in a sublevel is singly occupied before any orbital is doubly occupied
- All of the electrons in singly occupied orbitals have the same spin
Pauli’s Exclusion
No two electrons in the same atom can be exactly the same
(1) no more than two electrons can occupy the same orbital
(2) two electrons in the same orbital must have opposite spins
What are the exceptions in electron configuration?
Chromium (24e-) and Copper (29e-)
Atom
Smallest building block that makes an element, they are metal
Element vs Compound
Element- substance made of one type of atom
Compound- substance made of more than one type of atom (CO2)
*both are examples of pure substance
Mixture
combination of different elements and/or compounds
*only physically combined, and can be separated
Molecule
Atoms bound together covalently with fixed size and shape (eg. CO2)-> always that formula
Lattice/crystal
Atoms bound ionically, not fixed in size or shape (eg. NaCl)-> requires ratio of 1:1
Ionic Bonding
Lose and gain electrons to form ions, where the ions are attracted to each other because of difference in charge (electrostatic attraction). Forms lattice.
Covalent bonding
Shared electrons with no ions, form molecules and are held together by electrostatic attraction
