A32 gram radioactive sample has a half-life of 2 days how much of the original sample remains after 6 days

Chemistry answer as much as you can if you can't answer more then 2 don't answer

Why does his teacher ask him to balance the equation by including the correct coefficient

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.)