Scientists frequently use models in their investigation. which is a characteristics of all models?

Abullet found at a crime scene may be used as evidence in a trial if the percentage of metals match to the composition of metals in a bullet from the suspect's ammunition. a forensic scientist's analysis of the bullet shows that it contains 11.9 g of lead, 0.5 g of tin, and 0.8 b of antimony. what is the percentage of lead metal in the bullet? express your answers to the one's place.

Sodium sulfate dissolves as follows: na2so4(s) → 2na+(aq) + so42- (aq). how many moles of na2so4 are required to make 1.0 l of solution in which the na concentration is 0.10 m?

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