How do you determine if a material is a mixture or a substance?

List the path of the respiratory system

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.)

Reduction is a reaction which results in a in electrons and a in positive charge of the atom or ion 1) a- loss 1) b- gain 2) a-increase 2) b-decrease