Approximately what precent of parent isotopes remains after 0.5 half lives have passed

Which form of relativism states that people rely on their own standards of right and wrong when making a decision?

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)

How many moles of oxygen gas are produced from the decomposition of six moles of potassium chlorate