lesson 7 alpha scattering experiment

Question 1

1000 years ago, the ancient Greeks believed everything was made from of

Answer 1

atoms

Question 2

ancient Greeks believed atoms are what

Answer 2

tiny spheres that cannot be divided

Question 3

how long was the ancient Greeks idea of atoms accepted for

Answer 3

hundereds of years

Question 4

in 1897 what did scientists discover

Answer 4

atoms contain tiny negative particles

Question 5

in 1897 what did the scientists call the tiny negative particles

Answer 5

electrons

Question 6

what did the discovery of electrons tell scientists

Answer 6

that atoms are not tiny spheres that cannot be divided

Question 7

scientists believed what after concluding atoms are not tiny spheres that cannot be divided

Answer 7

instead the believed atoms must have an internal structure

Question 8

scientists suggested a new model for the structure of atoms, called what

Answer 8

the plum pudding model

Question 9

in the plum pudding model, the atom is what

Answer 9

a ball of positive charge, with negative electrons embedded in it

Question 10

which experiment was carried out to figure out if the plum pudding model was correct

Answer 10

the alpha scattering experiment

Question 11

why is the alpha scattering experiment one of the most important in science

Answer 11

because it radically changed the way we think about atoms

Question 12

what was the first step of the alpha scattering experiment (step 1)

Answer 12

scientists took a piece of gold foil

Question 13

why did scientists use a ‘gold’ foil for the alpha scattering experiment

-how many atoms thick

Answer 13

as we can hammer gold into a very thin foil

-just a few atoms thick

Question 14

scientists then did what after taking a piece of gold foil (step 2)

Answer 14

fired tiny particles at the gold foil

Question 15

what are the tiny particles called that were fired at the gold foil

Answer 15

alpha particles

Question 16

which charge are alpha particles

Answer 16

positive charge

Question 17

scientists found most of the alpha particles pass through the gold foil in what way

Answer 17

they passed through the gold foil, without changing direction

Question 18

sometimes what would happen to the alpha particle as it would pass its way through the gold foil

Answer 18

it would deflect
(change direction)

Question 19

sometimes the alpha particle would do what

Answer 19

bounce straight off the gold foil

Question 20

the fact that most of the alpha particles went straight through the gold foil interpreted what

Answer 20

that atoms are mainly empty space

Question 21

the fact that the scientists interpreted that atoms were mainly empty spaced made them realise what

Answer 21

that the plum pudding model had to be wrong

Question 22

secondly because some of the alpha particles were deflected, interpreted what

Answer 22

that the centre of the atom must have a positive charge

Question 23

alpha particles are positive, so any alpha particle that comes close to the positive centre of the atom would what

Answer 23

repel and change direction

Question 24

Finally because some alpha particles bounced straight back interpreted what

Answer 24

that the centre of an atom must contain a great deal of mass

Question 25

we now call the central part of the atom the what

Answer 25

nucleus

Question 26

From the results of the alpha scattering experiment, scientists replaced the plum pudding model with what

Answer 26

the nuclear model

Question 27

in the nuclear model, most the atom is what

Answer 27

simply empty space

Question 28

in the centre of the atom in the nuclear model, what do we have

Answer 28

a tiny positive nucleus, containing most the mass of an atom

Question 29

around the edge of an atom in the nuclear model, what do we have

Answer 29

negative electrons

Question 30

new experimental evidence, led the change of a plum pudding model to a wat

Answer 30

nuclear model