P1- Matter Flashcards
What did Thompson discover
The existance of the electron
What where Thompsons ideas about the atom
An atom is a ball of positive charge with negative electrons embedded in it
What was Rutherfords Atomic model called
The nueclear atom
What was the experiment Rutherford conducted
Positively charged alpha particles were fired at thin gold foil.
What where the results of Rutherfords experiment
- Most when straight through
- A few partially deflected
- Some fully reflected
Why did some of the alpha particles fully reflect
Rutherfords experiment
Because they where reppled by the negitive electrons.
What did Rutherford conclude from his experiment
- the mass of an atom is concentrated at its centre, the nucleus
- the nucleus is positively charged
What was Bohrs atom models name
planetary model
What did Bohr discover
The idea that electrons are found in shells (rings)
What is the typical size of atoms or small molecules
1 × 10^(–10)m
Define density
How closely packed the particles are in a solid, liquid or gas
Mass is always __________
Conserved
What two things can happen when you heat up a substance
- The energy stored increaces
- A change in state
Define Specific heat capacity
The amount of heat energy required to raise the temperature of 1 kilogram of the substance by 1 degree Celsius
Define Specific latent heat of fusion
The energy required to change the state of 1 kg of substance
How do you increase preasure in a gass
- Reduce the container size
- Increase the tempurature
- Add more gass
Why do the factors that increace pressure in gasses have that effect
Because the change causes there to be more frequent collisions with the container which exert an increased force.
Can gasses be compressed
Yes gas is the only state that can be
What happens when a gass is compressed
The pressure increaces
What is the type of Pressure exterted on a force by pressure
Pressure produces a net force
at right angles to any surface
What does work do to a Gas
It can increase the tempurature
Why does atmosphereric pressure vary with height
- More or less particles above us
- More or less gravational pull
What causes something to float
If the objects denisity is lower than the substance it is submerged in
