You are using a Geiger counter to measure the activity of a radioactive substance over the course of several minutes. If the reading of 400. counts has diminished to 100. counts after 57.9 minutes, What is the half-life of this substance?

Which statements correctly match a chemical name with its formula? use the list of polyatomic ions and the periodic table to you answer. the chemical formula for ammonium carbonate is nh4hco3. the chemical formula for ammonium hypochlorite is nh4clo. the chemical formula for ammonium nitrate is nh4no3. the chemical formula for ammonium phosphate is nh4(po4)3. the chemical formula for ammonium sulfate is (nh4)2so3.