Revision_Alpha Scattering

The nuclide ²³⁸₉₂ U decays by emitting α-particles and β-particles in a series of decays to form ²⁰⁶₈₂Pb. Eight α-particles are emitted in the sequence. How many β-particles are emitted?

• 6

• 8

• 10

• 12

An isotope of uranium, with proton number 92 and nucleon number 235, emits a series of

a-particles and β-particles. What is the proton number and nucleon number after five

a-particles and two β-particles are emitted?

• A

• B

• C

• D

What can be assumed to be the maximum range of an a-particle in air?

• a few millimetres

• a few centimetres

• a few metres

• a few kilometres

In an α-particle scattering experiment a very thin gold film is bombarded with α-particles.

What is observed?

• A few α-particles are deflected through an angle greater than 90º.

• Most α-particles are deflected through angles greater than 90º.

• No α-particle continues on its original path.

• No α-particle is deflected through an angle greater than 90º.

What can be concluded about a gold nucleus when α-particles are scattered by a thin gold foil?

• The nucleus contains protons.

• The nucleus contains neutrons.

• The nucleus is much smaller than the size of the atom.

• The nucleus is surrounded by electrons.