HELPPP PLS 7.) All isotopes of element T are radioactive, but they have widely varying half-lives. If an 1600.0 g sample of element T decays to 100.0 g of in 639,000 years, what is the amount of time needed for ONE half life to go by?

150.0 grams of asf3 were reacted with 180.0 g of ccl4 to produce ascl3 and ccl2f2. if the actual yield of ccl2f2 was 127 g, what is the percent yield?

In 1901, thomas edison invented the nickel-iron battery. the following reaction takes place in the battery. fe(s) + 2 nio(oh)(s) + 2 h2o(l) fe(oh)2(s) + 2 ni(oh)2(aq) how many mole of fe(oh)2, is produced when 5.35 mol fe and 7.65 mol nio(oh) react?

What is the area in square meters of 448 g ai foil that has a thickness of 23921 nm? the density is 2.70 g/cm