Atomic Structure- Development of Model of Atom

Question 1

J.J. Thompson discovered the ________ (tiny negatively charged particles) and described atoms like ‘____ _________’ with negative charges embedded in a cloud of positive charge.

Answer 1

J.J. Thompson discovered the electron (tiny negatively charged particle) and described atoms like ‘plum puddings’ with negative charges embedded in a cloud of positive charge.

Question 2

Geiger and Marsden’s did experiments firing positive _____ particles at ____foil which showed atoms could not be _____.

Answer 2

Geiger and Marsden’s did experiments firing positive alpha particles at gold foil which showed atoms could not be solid.

Question 3

__________ proposed that the positive charge of an atom is in a small centre which he called the nucleus and electrons _____ this nucleus. (This is the _______ model)

Answer 3

Rutherford proposed that the positive charge of an atom is in a small centre which he called the nucleus and electrons orbit this nucleus. ( This is the nuclear model)

Question 4

In 1914 Niels ____ suggested electrons orbit at set distances in ______ _______ (or shells)

Answer 4

In 1914 Niels Bohr suggested electrons orbit at set distances in energy levels (or shells)

Question 5

In 1932 James Chadwick discovered the _______ which has __ ______ and has the same ____ as a proton

Answer 5

In 1932 James Chadwick discovered the neutron which has no charge and has the same mass as a proton

Question 6

Dalton thought atoms were hard ________ and that elements had only ___ ____ of atom.

Answer 6

Dalton thought atoms were hard spheres and that elements had only one type of atom.