c1 Flashcards
(22 cards)
solids
particles in regular arrangement (lattice)
vibrate around fixed positions
cannot be compressed
strong electrostatic forces
liquids
particles have no regular arrangement
able to move past each other
cannot be compressed
strong but not as strong as solids electrostatic forces
gases
particles are far apart
move randomly at fast speeds ( high energy)
can be compressed
weak electrostatic forces
changes in state
solid -> gas = sublimation
gas -> solid = deposition
to melt/evaporate
energy (heat) is required to overcome the electrostatic forces of attraction between particles to melt/evaporate
physical change
reversible, no new substances made
particle arrangement and movement change
chemical change
irreversible, new substances made
particles break up and join together in different ways
limitations of particle model
forces between particles
size of particles
space between particles
protons neutrons and electrons
protons +1 and 1 mass
neutrons 0 and 1 mass
electrons -1 and 0.0005 mass
size of atom
1 x 10⁻¹⁰ meters
size of nucleus
1 x 10⁻¹⁴ meters
mass number
total no. of protons and neutrons
atomic number
total no. of protons
isotope
forms of the same element but with the same number of protons and different number of neutrons
ions
charged particles due to the gain or loss of electrons
dalton
all matter made from atoms
all atoms of an element are identical
different elements contain different atoms
j.j thomson
discovered electron
atoms contained electrons
atoms neutral overall
plum pudding model - positive mass with negative electrons randomly dotted around
rutherford
gold foil experiment
fired alpha particles (positively charged particles) at thin gold foil
expected particles to go straight through, but many changed directions and some even completely deflected back
results suggested there was large positive mass in atom (nucleus)
rutherford also suggested that electrons orbit around nucleus
bohr
electrons orbit around in shells
relative formula mass
Mg(OH)2 (small 2)
(24.3x1)+(16x2)+(1x2) = 58.3
empirical formula
C5H10 -> CH2
