Atomic Structure

The following scientists all produced theories about the atom. Place them in chronological order, starting with the earliest.

•     Rutherford, Dalton, Thomson, Bohr.

• Dalton, Rutherford, Thomson, Bohr.

•     Dalton, Thomson, Rutherford, Bohr.

Atoms have no overall charge because…

• the number of protons, neutrons and electrons are equal

•    the number of protons and electrons are equal

• the number of protons and neutrons are equal

How many protons, electrons and neutrons does sodium have?

•     11 protons, 11 electrons, 12 neutrons

•   12 protons, 12 electrons, 11 neutrons

•     11 protons, 11 electrons, 11 neutrons

Which type of radiation can penetrate paper but not aluminium?

•   Alpha particles

• Beta particles

• Gamma particles

What is the hazard symbol for radiation?

• 
• 
• 

 The initial activity of a sample is 320Bq. What would be the activity after two half-lives?

• 620Bq

• 132Bq

• 80Bq

Irradiation means…

• a material is radioactive.

• a material has been exposed to radiation.

• radiation has entered a body.

What happens in alpha decay?

•      Decreased charge and decreased mass.

• Decreased charge and increased mass.

•      Increased charge and increased mass.

Beta particles are…

• high-speed neutrons.

• high-speed protons.

• high-speed electrons.