C1 Atomic Structure

Question 1

John Dalton’s discovery

Answer 1

(start of the 19th century) Atoms were first described as solid spheres

Question 2

JJ Thomson’s discovery

Answer 2

(1897) Plum pudding model-the atom is a ball of charge with electrons scattered

Question 3

Ernest Rutherford’s discovery

Answer 3

(1909) Alpha scattering experiment-mass concentrated at the centre; the nucleus is charged. Most of the mass is in the nucleus. Most atoms are empty space

Question 4

Niels Bohr’s discovery

Answer 4

(1911) Electrons are in shells orbiting the nucleus

Question 5

James Chadwick’s discovery

Answer 5

(1940) Discovered that there are neutrons in the nucleus

Question 6

Isotopes

Answer 6

Atoms of the same element with different numbers of neutrons

Question 7

What determines the way an element will react?

Answer 7

The number of electrons in the outermost shell of an element’s atoms