history of the atom - SC3

Question 1

Explain the 3 parts of John Dalton’s theory (hint, solid sphere man)

Answer 1

3 parts made in 1803 -

Everything is made of atoms

Atoms of the same element are exactly alike

Atoms join with other atoms to form new substances

Question 2

Describe J.J Thompson’s era (hint - plum pudding guy)

Answer 2

Made in 1897

used a cathode ray tube

found atoms can be divided into smaller parts

experiment proved particles are negatively charged (discovered electrons)

plum pudding model composed of negatively charged electrons scattered in a positively charged blob

Question 3

Rutherford (hint - gold foil experiment)

Answer 3

In 1909

shot a beam of positively charged electrons into a thin sheet of gold foil

(result: most passed through however more than predicted were reflected, some even bouncing straight back)

Invented nuclear atom theory - tiny positively charged nucleus’ at the centre surrounded by a ‘cloud’ of negative electrons

Question 4

Bohr (hint: Bohr’s model)

Answer 4

A model created where electrons were placed in shells