A gas that has a volume of 28 liters, a temperature of 45 °C, and an unknown pressure has its
volume increased to 34 liters and its temperature decreased to 35 °C. If I measure the pressure
after the change to be 2.0 atm, what was the original pressure of the gas?

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

This classification of drug typically changes the brain's chemistry and reduces its ability to create its own endorphins.

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled