there are 25 elements found in living things. how many of these elements are found in some organisms but not at all?

If 518.0 g sample of a metal has a volume of 2.00mL what is the density of the metal

A hydrocarbon with general formaul cxhy is burned completely in air yielding 0.18 g of water and 0.44 g of carbon dioxide. Which formula could give such data?

A solution contains some or all of the following ions: Sn4+, Ag+, and Pb2+. The solution is treated as described below: Test 1) Addition of 6 M HCl causes a precipitate to form. Test 2) Addition of H2S and 0.

Why do oxygen molecules have a double bond with carbon?

If the ozone layer gets significantly thinner in your lifetime, what changes do you need to make in your lifestyle?

What happens to an isotopes during radioactive

Why does the effective nuclear charge increase across a row of the periodic table?

Iodine-131 decays to form xenon-131. the half-life of this reaction is 8.07 days. from a 200-g sample of iodine-131, how much of the sample is xenon-131 after 16.14 days?

Complete the following statement by checking all that apply Creativity allows scientists to develop multiple approaches to solving problems. adapt to changes in scientific knowledge. look at old problems in new ways.

The atomic weight of hydrogen is 1.00794. a. True b. False