Suppose you found a bone of a mastodon which had 6.25%c14and93.75%n14 how long ago did this animal die

t= 3886.18 years old

Explanation:

Whenever an animal dies de C14 and N14 begin to disintegrate in such a way that the proportion between C14 and C12 decreases, with a semi-disintegration period of 5.730 years, T. To get to know how long it takes an element to disintegrate, we must use this semi-disintegration period, which is the time it takes until the amount of the element is reduced to its half.  

We can find the age of the fossil, t, by using the next formula:

t = - (T x ln (C14))/ ln (2)

t = - (5730 x ln (0.625)/0.693

t= - (-2693.12)/0.693

t= 3886.18  

a. by using fur or clothes to trap heat energy near the body

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.