Grade 7 DA#2 A group of scientists is developing a small, working model of a solar-powered heating and cooling system. What is the purpose of building this model?

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.

Explanation for basic character?

Idont understand it 1.what is the boiling point of a solution of 675 grams of ethylene glycol (c2h6o2) in 2.50 liters of water?