If a radioactive substance's half-life is 20 years, how much of a 40-gram sample will be left after 60 years? a. 5 grams b. 10 grams c. 20 grams d. 30 grams

Why are adults bigger than they were as children biology

Some mining processes involve removal of large areas of earths surface in the mined region this practice causes severe environmental damage by allowing which natural process to accelerate in the affected areas? a.precipitation b.erosion c.migration d.condensation

Drag each label to the correct location on the chart. match the function to the type of tissue