The half-life of radon-222 is 3.8 days. Calculate how long a 48g sample of radon will last before it contains only 3g of radon and stops being effective (2 marks)

What mass of glucose is produced when 54g of water react with carbon dioxide

Rank the four gases (air, exhaled air, gas produced from from decomposition of h2o2, gas from decomposition of nahco3) in order of increasing concentration of co2

The comparison of the number of atoms in a copper coin the size of a penny with the number of people on earth is made to illustrate which of the following? a. that atoms are indivisible b. that atoms are very small c. that atoms are very large d. that in a copper penny, there is one atom for every person on earth