Concept radiometric dating
However, oxygen atoms can have between 8 and 10 neutrons in the nucleus and therefore the isotopes of oxygen have atomic masses of 16, 17, and 18 a.m.u.(and none are radioactive! Samarium (Sm) has 7 naturally occurring isotopes (3 are radioactive).
Remind them that geologists only use certain radioactive isotopes to date rocks.
If they can begin to comprehend that it is random and spontaneous, they end up feeling less nervous about the whole thing.
Radiometric dating is the method of obtaining a rock's age by measuring the relative abundance of radioactive and radiogenic isotopes.
The atoms that are involved in radioactive decay are called isotopes.
In reality, every atom is an isotope of one element or another.
Using demonstrations of half-life such as a coin toss for large classes or M&M demonstration for smaller classes can help students to better understand what is happening.
Plotting the results of these demonstrations results in a curve of an exponential decay function.