alpha scattering experiment

Question 1

what did scientists discover in 1897?

Answer 1

atoms contain tiny negative particles called electron

Question 2

what did the plum pudding model suggest?

Answer 2

that an atom is a ball of positive charge filled with negative electrons inside.

Question 3

what experiment was used to discover if the plum pudding model was correct or not?

Answer 3

the alpha scattering experiment

Question 4

what was the alpha scattering experiment?

Answer 4

1. first scientists took a piece of gold foil
2. they then fired the positive alpha particles at the gold
3. most of the alpha particles passed straight through without changing direction
   4.some alpha particles were deflected because they had hit close to the positive nucleus
   , some alpha particles had bounced straight back because they had hit the positive nucleus

Question 5

in the alpha scattering experiment

why did scientists use a piece of gold foil?

Answer 5

this is because we can hammer gold out into very thin foil ( just a few atoms thick)

Question 6

the fact that most alpha particles went straight through the gold atoms told us that…

Answer 6

atoms are mainly empty space

the plum pudding model had to be wrong

Question 7

when an alpha particle bounces straight back what does this mean?

Answer 7

has hit the centre (nucleus) the centre of an atom must contain a great deal of mass.

Question 8

what replaced the plum pudding model?

Answer 8

the nuclear model

Question 9

what does the nuclear model suggest?

Answer 9

an atom is mostly empty space
in the centre, a tiny positive nucleus
around the edge we’ve got negative electrons