If you are given a 2,900-gram sample of Hydrogen, and hydrogen has a half-life of 2,450 years. How much hydrogen is left after 19,600 years?

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?

Which of the following is a physical property flammability heat of combustion solubility and toxicity

Which of your 24 wells had indications that a chemical reaction occurred? how were you able to tell that a chemical reaction occurred? which of your 24 wells had indications that a physical reaction occurred? how were you able to tell that a physical reaction occurred? report on both mixing and evaporation. make a general statement about whether your hypotheses were validated or rejected. must your hypotheses be correct for this to be a successful laboratory?