When you rub a match against a rough surface, fire results, giving off light and heat. the law of conservation of energy says that energy cannot be created. how can you explain the fire seeming to come from nowhere?

Amedication is given at a dosage of 3.000 mg of medication per kg of body weight. if 0.1500 g of medication is given, then what was the patient's weight in pounds (lbs)? there are 453.59g in 1 lb.

The comparison of the number of atoms in a copper coin the size of a penny with the number of people on earth is made to illustrate which of the following? a. that atoms are indivisible b. that atoms are very small c. that atoms are very large d. that in a copper penny, there is one atom for every person on earth

Pinene is an unsaturated hydrocarbon found in pine resin. if pinene has m+ = 136 and contains 1 double bond(s) and 2 ring(s); what is its molecular formula? enter the formula in the form ch first, then all other atoms in alphabetical order; do not use subscripts. the formula is case-sensitive