What describes using organisms that were only alive during a specific time period to estimate the unknown age of items? radioactive dating law of superposition relative dating index fossils

Radioactive dating describes the use of organisms that were alive only during a specific time period to estimate the unknown age of items.  

Explanation:

Radioactive isotopes are used in radio-active dating. According to the isotope used each dating technique has got different names. In radioactive dating traces of radioactive materials trapped inside rocks and minerals are analysed to determine their ages.

In potassium-argon dating, potassium-40 decays to argon-40.  In rubidium-strontium dating , rubidium-87 decays to strontium-87. In carbon dating carbon-14 isotope is used. Uranium-lead dating, samarium-neodymium dating etc are examples of some other dating methods.

the correct answer is - ability to find a mate

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.