What is the density of a 6 g of pure copper with a volume of 12 mL? a 0.25 g/mL
b 1.5 g/mL
c 2.3 g/mL
d 0.5 g/mL

Asingle atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it? ok o z

If 10.0 ml of the solution on the right are withdrawn from the 100 ml beaker and diluted again in a similar manner, what is the new concentration? m nacl

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?