wee are all full of isotopes
This is important because each isotope has different properties.
The most important isotope of promethium is Pm-147.
Iodine-131 (not iodone) is a radioactive isotope of iodine: this isotope has important applications in the treatment of thyroid diseases.
For the nuclear reactors and nuclear weapons the isotope plutonium-239 is important.
Isotopes are very important part of calculations in chemistry. They are different elements of same atomic number.
The most important is carbon-12.
if he is really cool... he will borrow your calculaator >=}
The atomic particles of an isotope are the proton, electron and neutron
The word substance is used in chemistry to describe elements or compounds. It is used because when dealing with an unknown substance, it is important to not assign either name to it.
The half-life of an isotope is how long it takes for half of the atoms in a mass to undergo radioactive decay. Say you have 40g of an elements isotope with a half-life of one year. After 1 year, there would be 20g of that isotope left, and 20g of a different isotope/element. After 2 years, there would be 10g, and so on...
The half life of the most important isotope (241Am) is 432,2 years.
The number of neutrons in an atom depends on the isotope. The most common sulfur isotope has 16. The average number of neutrons in an atom of sulfur is about 32.065.