The Moon is slowly moving away from the Earth at a rate of about 4 centimeters a year. In one billion years the Moon will be 40,000 kilometers farther away from the Earth than
it is today. How will this affect the tides of Earth. Use your notes for reference.

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.

It is a ok  i know i have a brain functioning well.