Want to make creations as awesome as this one?





8. Thanks

4. Dating the Age of Rocks

3. Example of radioactive dating

7. Radiocarbon Dating

2. Half-Life of carbon-14

6. Living VS Non-Living Matter

5. Video

1. What radioactive dating is?


Chapter 01

What radioactive dating is?

Radioactive dating consists of a variety of methods that use radioisotopes to measure the age of minerals and organic matter. The most common method is radiocarbon dating, which is used to find the age of organic matter, which originated from trees and animals. There are also techniques that find the age of inorganic materials like rocks and minerals.


Chapter 2

Half-Life of carbon-14

The half-life of carbon-14 is 5600 years. Carbon-14 can be found in dead plants or animal materials. When carbon-14 reaches its half-life that means that the carbon-14 that is found on the dead plants or animal materials will also halve. In case to estimate the amount of carbon-14 in a sample that is found we are measuring the activity of the sample. The activity of carbon-14 that is found compared with the amount of carbon-14 that would have been present when the sample was part of a living organism it is possible to estimate when the source of the sample died.


Chapter 3

Example of radioactive dating

The first thing we should do is to find the half-life of the Bq:6 Bq = 24 : 2 : 2Since the activity of the sample has halved twice from that expected in living wood, two half-lives must have passed Finally, the age of the sample must be:2 x 5600years = 11.200 years

120 g of living wood has a radioactive activity of 24 Bq (Becquerel). A 120 g sample of wood from an historical site is found to have an activity of 6 Bq. If the half-life of carbon-14 is 5600 years, estimate the age of the wood from the site.

How to estimate the age of wood

Chapter 4

Dating the Age of Rocks

As non-living matter like rocks cannot absorb carbon-14 (which is used in radiocarbon dating) alternate techniques are used. When a radioactive substance decays it transforms into a different element, which can be of the same or a different element. The original radioisotope is the parent nuclide and the new radioisotope is the daughter nuclide. Both the parent and the daughter isotopes decay. When the parent isotope decays it creates a decay series which consists of different elements. The decay series ends when a stable isotope is created, or one that cannot decay further.


So as to find the age of rocks we measure the proportion of parent nuclides to stable daughter nuclides. The half-life of most radioactive parent isotopes is extremely long, in some cases greater than the lifetime of earth. For example the half-life of potassium-40 is 1.25 billion years, and the decay series ends with argon-40.


Chapter 5



Chapter 6

Living VSNon-Living Matter

  • They don't have carbon-14
  • They aren't made up of cells
  • They don't have a definite life cycle
  • They don't require food, air and water
  • They respond to changes around them
  • They don't grow

non-living matter

  • They have carbon-14
  • They are made up of living cells
  • They have a definite life span after which they die
  • They require food, air and water
  • They respond to changes around them
  • They grow

Living matter


Chapter 7

Radiocarbon Dating

Radiocarbon dating measures the level of an isotope called carbon-14, which is made in the atmosphere. Cosmic rays from space have a lot of energy, which when it hits the atoms of gas in the atmosphere it breaks apart the nuclei. The parts of the broken nuclei travel at high speeds and if they hit other atoms a nuclear transformation happens. The nuclear transformations turn the elements in the air into different isotopes. One such transformation is when a fast-moving neutron collides with an atom of nitrogen. The result of that collision is that the nitrogen atom transforms into an atom of carbon-14.


Isotopes have the same chemical behaviour meaning that carbon-14 (C-14)can react with oxygen in our atmosphere forming carbon dioxide (carbon-12). When this process is finished carbon dioxide is then absorbed by plants 🪴 in the process known as photosynthesis. After that, a proportion of carbon that makes up any plant will be carbon-14 (radioactive form).


On this point, we should mention that carbon-14 enters our food chain which means that animals and humans have a proportion of carbon-14 in their bodies. The carbon-14 in human bodies will be released but in living plants and animals, carbon-14 will be continuously replaced by new ones. When an organism dies the replacement process will stop and by the time radioactive carbon will be decayed from the plant or animal. Also, the remaining proportion of radioactive on the plant or animal compared with the stable carbon isotope will be decreased.