A scientist is using potassium-40, which is a radioactive isotope of potassium, to find the absolute age of a fossil by radiometric dating. The scientist determines that about three-fourths of the original potassium-40 atoms in the fossil now remain in the fossil. What additional information is necessary for the scientist to determine the absolute age of the fossil?
A. the half-life of potassium-40
B. the identity of an index fossil
C. the atomic mass of potassium-40
D. the total mass of the fossil

How many chromosomes are in a gold fish?

When a human or animal consumes food, the carbon in that food is most likely to be converted into which of the following elements? a. carbon remains carbon b. nitrogen c. oxygen d. hydrogen

The lake of the ozarks is a human-made lake, so it collects runoff from coal strip-mining, fertilizers, resort wastewaters, and septic drainages. the average lake temperature is between 10∘c and 21∘c. consider the physical requirements for growth and multiplication that would allow fecal coliforms to “blossom” in the lake of the ozarks. which of the following would accurately describe these organisms? check all that apply. psychrophiles facultative halophiles extremophiles mesophiles hyperthermophiles