P1 Atoms And Particles Flashcards
Aristotle
All matter is made of fire, earth, air, water and aether
Demokritos
Matter is composed of tiny invisble particles, atoms.
John Dalton
All Matter is atoms
Atoms are indestructible
All atoms of a particular element are identical
Compounds are formed when two or more different kinds of atoms join
JJ Thomson
Studied rays given out by hot metals
These were called cathode rays
They were made from particles 1000th the mass of hydrogen
These are called electrons
And have a negative charge
PLUM PUDDING MODLE
Plum pudding model
JJ Thomson
All atoms are neutral
The sponge is positive
The plums are electrons (negative)
Rutherford
GOLD FOIL
result 1 : most particles went straight through the gold foil meaning most of the atom is empty space
Result 2 : a small number bounced back to detector meaning mass of atom is mostly concentrated in centre
Result 3: some of the particles were deflected at large angles meaning the centre of the mass is positively charged and rebels alpha particles when they pass nearby
James Chadwick
Discovers the neutron in the nucleus
Niels Bohr
Electrons circle the nucleus at high speed
Electrons are kept in certain energy levels in a stable formation around the atomic nucleus
Diameter of an atom
1x10 ^ -10m
What is density
Density is a measure of how much matter there is in a given volume
What equipment do we use to measure density
A displacement can and water
When a force is applied to a surface it will …
Cause pressure
What is absolute zero ( zero kelvin)
-237.14 degrees Celsius
What are the 3 properties of gas
Volume
Temperature
Pressure
Boyle’s law
Pressure is inversely proportional to volume
Pressure is directly proportional to the inverse of volume
