Lesson 1 - Atomic Theory Flashcards
Matter
- Anything with a mass and volume
- Can be solid liquid or gas
- Divided into mixtures and pure substances
Mixtures
- Can be heterogeneous: see diff parts. COLLOIDS AND SUSPENSIONS
- Cab be homogenous: Uniform appearance. SOLUTIONS AND ALLOYS
Pure substances
- Only one type of particle
- Can be element or a compound
Atomism
- Matter is composed of tiny particles that move through surrounding space.
John Dalton
• atomic theory in 1803.
• Matter composed of tiny, indestructible particles called atoms.
• Atoms of same element are identical to one another (mass, size, shape).
• Chemical reactions = rearrangement of atoms.
• Billiard ball model.
J.J Thompson
• Discovered that matter contains tiny, charged particles, electrons.
• Plum pudding model
• Atom consists of positive sphere with negative particles scattered throughout.
Ernest Rutherford
•Proved existence of a positively charged nucleus
• Gold foil experiment
• Solar system model
James Chadwick
In 1932, Chadwick proved the existence of neutral neutrons in the nucleus.
Erwin Shrodinger
- Proposed the quantum Erwin Shrodinger’s Model mechanical model of the atom.
• Electron
Cloud Model - A negative cloud surrounding a positive nucleus.
Metals
Lose electrons
Good conductors
malleable, ductile, shiny
Non-metals
gain electrons
form covalent bonds
poor conductors
brittle, nonducile
Metaloidd
properties lf metals and non metals.
Some conduct electricity and some don’t
straddle the staircase
Alkali metals
1 valence electrons
ready to lose in ionic bond
react vigorously with water
alkaline earth metals
2 valence electrons
ready to lose
Halogens
7 valence electrons
aggressively seek 1 more