1.2.1 Atomic Structure: History

The infamous 'paddle wheel' experiment demonstrated properties of cathode rays [pick two]

• Cathode rays travel in straight lines

• Cathode rays travel from negative terminal to positive terminal

• Cathode rays produce a fluorescence

• Cathode rays are negatively charged

Who discovered the neutron?

• Chadwick

• Rutherford

• Gallagher

• Mosely

Identify the scientist who detected the presence of cathode rays

• Crookes

• Millikan

• Rutherford

• Dalton

Name the scientist who discovered the correct structure of an atom

• Thompson

• Chadwick

• Rutherford

Why did most alpha particles go straight through the atom undeflected?

• Alpha particles are too small

• Alpha particles don't have much mass

• The atom is mostly empty space

• Sub-atomic particles are missing

Some alpha particles were deflected at large angles. Why?

• Alpha Particles deflected due to hitting the nucleus slightly

• Alpha Particles deflected due to hitting the nucleus dead on

• Electromagnetic radiation

What happens to the very few alpha particles hitting the nucleus straight on?

• Deflected at an angle

• They go straight through

• Reflected right back along original path

Dalton proposed matter is made up of small indivisible atoms. True or False

• True

• False

Identify the scientist who classified cathode rays as sub atomic particles - Electrons

• Rutherford

• Chadwick

• Thompson

• Crookes

What was the purpose of Milikans 'Oil Drop' experiment?

• To find the charge of a proton

• To find the charge of a neutron

• To find the charge of an electron