Answer:
Atoms are made of the same type of parts,but the sizes change
Explanation:
What percent of potassium-40 remains undecayed in a rock that is 3.9 billion years old? The 3.9 billion year old rock has undergone three half-lives (3.9 divided by 1.3 = 3). After 3 half-lives, 12.5% of the potassium-40 remains undecayed.
Absolute Dating
AKA. RADIOMETRIC DATING
We can learn about the past by studying the present.
The Principle of Uniformitarianism states that current geological processes are the same processes that were at work in the past. This principle was proposed by Charles Lyell in the 1800's
Absolute Dating
Involves finding the absolute age (actual age) of a rock or fossil.
Elements that emit particles and energy are radioactive.
As radioactive elements emit particles and energy, they form new isotopes or elements.