Matter And Particles

Question 0

What was Rutherford’s atom?

Answer 0

Central positive nucleus surrounded by orbiting electrons

Question 1

What was Thompson’s plum pudding atom?

Answer 1

Sphere of positive charge with electrons dotted around

Question 2

What was Bohr’s atom?

Answer 2

Central positive nucleus surrounded by electrons, in shells

Question 3

What is the atom like in its stable state?

Answer 3

The atom is electrically neutral. The number of protons is equal to the number of electrons.

Question 4

What does the top number represent in an atom?

Answer 4

Mass number, number of protons and neutrons in the nucleus

Question 5

What does the bottom number represent in an atom?

Answer 5

Atomic number which is the number of protons in the nucleus. It is also knows as the proton number.

Question 6

What’s an isotope?

Answer 6

Versions of the same element which have the same number of protons but a different number of neutrons in the nucleus

Question 7

Explain the Geiger-Masden Experiment

Answer 7

1. Alpha particles were fired at a thin sheet if gold leaf.
2. An alpha particle is a helium nucleus
3. the equipment is placed in an evacuated chamber in order to prevent the alpha particles colliding with air molecules
4. the alpha particles are focussed to a narrow beam

Question 8

Explain what was observed during the Geiger-Masden experiment

Answer 8

1. The majority of the particles pass straight thought
2. some alpha particles are deflected
3. very few particles rebound straight back

Question 9

What’s the conclusion for the Geiger-Masden experiment

Answer 9

1. the particles that passes-the atom consist largely of empty space
2. the particles that deflected slight-the atom contains opposite charge
3. the particles that rebounded-most of the mass in an atom is concentrated in a small, dense region at the centre of the atom know as the nucleus

Question 10

What does Density depend on?

Answer 10

1. how closely packed particles are in a substance

2. the mass of the individual atoms of a substance

Question 11

How is Density calculated?

Answer 11

D(kg/m^3)=m(kg)/V(m^3)

Question 12

How can Density be measured?

Answer 12

It can also be measured in g/cm^3 but never mix the units

Question 13

What does Boyle’s Law State?

Answer 13

It states that for a fixed mass of gas at constant temperature the pressure is inversely proportional to the volume

Question 14

What is equation for Pressure and Volume?

Answer 14

P1V1=P2V2

Question 15

Explain Brownian Motion with smoke

Answer 15

1. particles of smoke appear to move around randomly in all direction
2. the particles of smoke are being bombarded by air molecules

Question 16

Explain Brownian motion with pollen grains

Answer 16

1. Robert Brown observed tiny grains of pollen suspended into water
2. the grains appeared to move around randomly in all direction
3. the grains of the pollen are being bombarded by the water molecules