If one assumes that a penny is a simple cylinder with a diameter of 19.0 mm and a height of 1.5 mm, what is the approximate thickness of copper on the penny (the density of copper is 8.93 g/mL):

Which of the following are correct values for the ideal gas laws constant r

What is true for a substance that releases energy

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world