Uranium, an important component of both nuclear weapons and nuclear reactors, has two major isotopes—U-238, which has a half-life of approximately 4.5 billion years, and U-235, which has a half-life of approximately 700 million years. Both were present in equal amounts at the time of the creation of the Earth, 4.5 billion years ago. How many billion years after the creation of the Earth had the amount of radiation from uranium decayed to half the amount present at the time of the creation of the Earth? (Round your answer to the nearest hundredth of a billion years.)

The half-life of Uranium-235 is 700 million years, which makes it useful for dating meteorites. If a meteorite has been determined to have 40% of its original amount of uranium, how old is it?

The half-life of Carbon-14 is 6,000 years. How old is an object that started with 10,000 Carbon-14 (parent) atoms and now has 2,500 (daughter) Carbon-14 atoms?

The radioactive element carbon - 14 has a half life of 5715 years. If a piece of charcoal from an ancient campsite has 20% of its original amount of carbon remaining, determine its age

One of the unusual properties of water is that it expands as it freezes. As a result, ice is less dense than liquid water and floats atop it. Imagine that ice was denser than liquid water. Speculate how this would affect the development of life on Earth.

According to the Bat Man, bats live for about 40 years and eat about 1,000 mosquitoes per hour. That means a single bat can eat approximately 1.75 X 108 mosquitoes in its life. Is the Bat Man correct? Show all conversions and explain in complete sentences.

The abundance of 40K is 0.012% of total natural potassium. The human body is 0.25% potassium by mass. The half-life of 40K is 1.25 x 109 years.  What is the mass of potassium in a 70 kg human adult?

Carbon-14 is radioactive while Carbon-12 is stable.  In your body, the ratio of C-14 to C-12 is for every 10,000 C-14 atoms, there are 1 trillion (1,000,000,000,000) C-12 atoms.  This is the normal ratio for livings things.  In a piece of a sabre-tooth tiger bone, a scientist finds there are only 625 C-14 atoms for every 1 trillion C-12 atoms.How old is the sabre-tooth tiger bone? The half-life for Carbon-14 is 5730 years.

A team of biologists finds a mammoth frozen in permafrost. They analyze the fraction of Carbon-14 and Nitrogen-14 atoms in the mammoth.  They find that for every 1 Carbon-14 atom, there are 15 Nitrogen-14 atoms. Approximately how old is the mammoth?

C^14, a form of carbon that is used to find the age of fossils has a half life of 5730 years. how much of a 10 gram sample is left after 13,000 years?