Flashcards in Deck 4 = Physics 10/10/13-end Of Winter Term Deck (36):
0 degrease in kelvin?
What did the plumb pudding model look like?
-It was a positively charged sphere with negatively charged electrons floating around in it.
Thomson invented what?
-The plumb pudding model of the atom, because it looked like a plumb pudding. Negatively charged plumbs stuck into a soft doughy negatively charged football shaped sphere.
What did the rutherford experiment prove?
-The Rutherford experiment managed to disproved the famous plumb pudding model of an atom. Because they discovered the nucleus. They discovered that the atom is mostly empty space.
What did they do in the Rutherford experiment?
-Alpha particles were fired at the atom which was in a vacuum. they would then fire positively charged alpha particles at the atom, the positively charged alpha particles most of the time went straight through the atom but 1 in 5000 times it would be deflected by the positively charged nucleus. So the nucleus was found.
What would have happened to most of the Alpha particles in the Rutherford experiment?
-Most of the particles would go straight through the atom.
Why was the Rutherford experiment conducted in a vacuum?
-This was so the alpha particles would not bounce of the particles in the air.
What charge are alpha particles?
In the Rutherford experiment how were the alpha particles deflected and then registered?
-Not all the alpha particles bounced off the nucleus, some were slightly deflected, The alpha particles were then picked up by a Geiger counter that was moved around the circumference of the experiment area.
What is an isotope?
-To atoms are isotopes if they have the same number of protons, but a different number of neutrons.
What are the numbers are the letters?
-C= Carbon (carbon 14).
-14= the top number of protons and neutrons in the nucleus (nucleon number) This is also the mass number because the mass in in the nucleus.
-6= atomic number.
How do you work out the mass number?
-It is the number of neutrons and protons in the nucleus (nucleon number).
Observations you would make of Brownian motion?
-The random, zig-zag motion of smoke particles in the air, or pollen particles in water.
Explain Brownian motion?
-The pollen particles are colliding with water molecules that are to small to see, this is changing the direction of the pollen particles, so the appear to be moving in a random zig-zag motion.
What is the equation for density?
What is the equation for volume?
-v= length x depth x height (only works with cuboids).
How do you find the volume of a cylinder?
-"pye" x radius2 x height.
What is mass meaused in?
What is volume meaused in?
What is density meaused in?
Describe how to calculate the density of an irregularly shaped object?
-1) Find the weight of the object to dertermin its mass
-2) then use a Eureka can, and place the object in it and the water that comes out will be the volume of the object.
-3) you finally need to measure the amount of water with the measuring cylinder.
At 0K what will happen and will you be able to get 0K?
-At (0K) particles will have stopped moving completely, we will never be able to do this because there always needs to be something colder (with less kinetic energy) for the heat (energy) to be transferred. So you will never be able to have an object with no kinetic energy.
Temperature is what?
-It is actually how much kinetic energy the particles have.
How do you measure the density of an object if it floats? (the object is less dense then water)
-1) find the volume of a heavy object first.
-2) then you simply weigh down the other object with the weight.
-3) you then find the difference between the two objects.
What inaccuracy would you have with the eureka can experiment?
-If the eureka can is not completely filled, then the volume will be to small.
-If the measuring cylinder is not completely dry then the volume will be to big.
-Splash from lowering objects into the water may have an effect on the result.
What is the equation for pressure?
-Pressure= force/area P=F/A.
What is force measured in?
What is area measured in?
What is the motion of molecules in a gas?
-They are moving very fast and randomly.
Why does a gas exert a pressure on the walls of a container?
-Because the gas particles collide with the container walls in great numbers.
-Since this force is spread over the area of the container wall, the force is divided by the area is the pressure the gas exerts.
What effects does the temperature have on particles in the air?
-The spread of the gas particles increases.
-The number of times the gas particles collide with the walls, per second increases (an example would be a balloon getting bigger)
also the pressure of the gas.
-So long as the mass of the gas stays constant The temperature of the Gas will also stay constant.
Boyle's law equation?
-P1V1 = P2V2
What is pressure measured in?
What is equation for pressure when you have density?
-Pressure = "rho" pgh