A typical scuba tank has a volume of 11 liters and can support a diver for one hour. An adult breathes about 3 liters of air with each breath. How can an 11-liter tank give a diver enough oxygen for one hour?

This graph gives information on changes in sea ice extent in the arctic ocean over a 30-year span. the overall trend shows in the ice extent. to address the trend, scientists need to ask themselves, one direct consequence of the trend is that

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.

Which metal exist in liquid state and can be cut with knife ?