P1 Flashcards
What did Dalton’s model of the atom look like?
A very small indestructible sphere
What subatomic particle did Thomson discover?
The electron
What did Thomson’s model of the atom look like?
Also known as the plum-pudding model
He thought it looked like a positive mass with negative electrons in it
Explain the experiment Rutherford conducted
He shot positively charged alpha particles at fixed gold metal foil
It was done in an evacuated chamber to prevent air molecules from absorbing the alpha particles
A detector, made from a microscope, was used to observe the experiment. Each time an alpha particle hit the plate, you would see a spot of light.
Explain what was expected to happen, and what actually happened in Rutherford’s experiment, and why
Rutherford expected all of the alpha particles to go through the foil, and most did, but some bounced back
Rutherford, therefore, discovered that atoms had tiny positively charged nuclei
When the positively charged alpha particles would come near to a positively charged nucleus, it would repel, as like charges repel
What does Rutherford’s model look like?
A simplified version of what we have today
What did Bohr suggest was wrong with Rutherford’s model? What did he add?
Bohr suggested that if the electrons just kept spiralling the nucleus, eventually the two would crash
He suggested that electrons orbited in fixed orbits called electron shells
What does density tell you?
How much mass there is in a certain volume
What is the density equation?
Density(kg/m3)=mass(kg)/volume(m3)
What is the densest state of matter? Why?
Solid is the densest state of matter, as in 1cm3 of a substance in the solid-state, there are more particles than those present in a liquid or gas
What does temperature tell you?
The average kinetic energy of the particles
How do you convert degrees into kelvin?
degrees->kelvin=+273
kelvin-degrees=-273
What does energy depend on?
The arrangement of the particles and how fast they are moving
What is specific heat capacity?
The energy needed to raise the temperature of 1kg of a material by 1 kelvin
What is the change from solid to gas and gas to solid called?
solid->gas= subliming gas->solid= depositing
What are the two types of latent heat?
Specific latent heat of fusion
Specific latent heat of vaporization
What is specific latent heat of fusion?
The energy transferred when 1kg of a substance goes from a solid to liquid and vice versa
What is the specific latent heat of vaporization?
The energy transferred when 1kg of a substance goes from liquid to gas
What happens to gas pressure as you increase the temperature?
If you increase the temperature, the particles in the gas move faster
This means more often collisions with the surfaces of the container
This means the gas pressure also increases
What is gas pressure recorded in?
Pascals (Pa)
What is the relationship between Pressure and Volume?
The particles in the gas bounce off the container walls at 90 degrees
If the volume is halved, there would be more collisions with the walls, meaning the pressure is doubled
Pressure and Volume are inversely proportional
What is the atmosphere?
A single layer of gas that covers the Earth and protects it
What is atmospheric pressure?
The pressure exerted by gases in the atmosphere
What happens to atmospheric pressure as you go up?
It decreases, as there is less and less air pushing you down from above
What is the gravitational field strength on earth?
10N/Kg
What equation do you use to find the depth at which something floats
Weight/ density X GFS X area
What is a vector quantity? Give an example
A quantity that is measured with a direction and a magnitude, e.g force
What is a scalar quantity?
A quantity that is measured with only a magnitude
Why are speed and velocity different?
Velocity is a vector, as you can measure it as 15m/s south
Speed is a scalar quantity
What is acceleration?
The change in velocity per second
What is the equation for acceleration?
Final velocity- initial velocity / time
What is the equation of motion?
FV^2-IV^2= 2 X acceleration X Distance
FV=Final Velocity
IV= Initial Velocity
What is the equation for kinetic energy?
kinetic energy (J) = 0.5 X mass (kg) X speed (m/s)