Radioactive dating game phet answers
The next step is to measure the amounts of the parent and daughter isotopes in a sample of the rock unit.
This is done by chemical analyses in specially equipped laboratories with sophisticated instruments capable of very good accuracy and precision.
So, for example, every carbon atom contains six protons and six electrons, but the number of neutrons in each nucleus can be six, seven, or even eight.
Therefore, carbon has three isotopes, which are specified as carbon-12, carbon-13 and carbon-14 (figure 1). Comparison of stable and unstable atoms of the element carbon.
This process of changing the isotope of one element (designated as the parent) into the isotope of another element (referred to as the daughter) is called radioactive decay.
The atoms in each chemical element may vary slightly in the numbers of neutrons within their nuclei.
These slightly different atoms of the same chemical element are called isotopes of that element.
However, while the number of neutrons varies, every atom of any chemical element always has the same number of protons and electrons.
Geologists must first choose a suitable rock unit for dating.
They must find rocks that contain these parent radioisotopes, even if they are only present in minute amounts.
Some isotopes of some elements are radioactive; that is, they are unstable because their nuclei are too large.