Oxygen can be produced in the laboratory by the reaction 2KClO3———-> 2KCl+3O2

How much potassium chlorate is needed to produce 2.75 L of oxygen, collected over water at 37°C and 94.9 kPa? The vapor pressure of water at 37°C is 6.28 kPa.

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

An empty fuel tank can still contain and therefore can be even more dangerous than one full of liquid fuel.

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.