Scientists estimate earth's age to be 4.6 billion years. samarium has a half-life of approximately 106 billion years. from the present date, approximately how many more years must pass before a sample of samarium that was created at the beginning of earth's history contains 25 percent of the original parent material? 10 billion 26 billion 100 billion 206 billion

Option (D)

Explanation: The following steps are shown how decay takes place-

So from the above question, the total number of years for Samarium to contain 25% of its parent material will be (106+106)=212 billion years.

it can also be calculated from the radioactive decay formula.

Thus the most approximate option provided here is option (D).

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.