A gas occupies a volume of 498 ml at a pressure of 1.01 kPa. When the pressure is changed the volume becomes 477ml. If there has been no change in temperature, what is
the new pressure in kPa?

Boron has an average atomic mass of 10.81. one isotope of boron has a mass of 10.012938 and a relative abundance of 19.80 percent . the other isotope has a relative abundance of 80.20 percent what is the mass of that isotope? report two decimal places