S4 Atomic Structure and Radioactivity Quiz

In the simple model of an atom, X orbits around Y as shown. What are X and Y?

• negatively charged electron

• positively charged nucleus

• positively charged nucleus

• neutron

• negatively charged electron

A neutral atom consists of seventeen electrons and eighteen neutrons. What are its atomic number and nucleon number?

The atom, 55133X, is a neutral atom. How many protons, neutrons and electrons are in this atom?

The reading on a detector placed near a radioactive material is 536 counts per second. The background count rate is 44 counts per second. The half-life of the radioactive material is 34 hours. What is the reading on the detector after 68 hours?

• 44 counts per second

• 123 counts per second

• 134 counts per second

• 167 counts per second

Radioactive dating 14C was used to find the age of a wooden archaeological specimen. Measurements were taken in three situations where the following count rates were obtained. If the half-life of 14C is known to be 5700 years, what was the approximate age of the archaeological specimen?

• 2800 years

• 8500 years

• 11 400 years

• 17 100 years

When dealing with radioactive materials, there are possible dangers. Which statement is correct?

• Beta-particles can pass through skin and damage body cells.

• Materials that emit only alpha-particles must be kept in thick lead containers.

• Radioactive materials are safe to handle after two half-lives.

• Sources of gamma radiation are dangerous because they have long half-lives.

The following show different behavious of alpha, beta and gamma radiations. They are absorbed to different extents in solids. They behave differently in an electric field. They behave differently in a magnetic field. Figures A, B and C illustrate these behaviours. Which three labels in figures A, B and C refer to the same kind of radiation?

• L

• R

• L

• L

• X

The isotope 86222Rn decays in a sequence of emissions to form the isotope 82206Pb. It will either emit an -particle or a -particle at each stage of the decay sequence. What is the number of stages in the decay sequence?

• 20

• 16

• 8

• 4

Which type of electromagnetic radiation is produced during radioactive decay?

• alpha-particles

• beta-particles

• gamma-rays

• X-rays

The following shows an arrangement that is used to check whether the flour inside a cardboard packet is above a certain level. If the flour is above this level, the flour absorbs the radiation from the source so that it does not reach the detector. Which type of radiation is suitable to use?

• alpha-particles only

• beta-particles only

• gamma-rays only

• either alpha-particles or beta-particles