Mendeleev's periodic table of elements was organized by
a. atomic number
b. number of electrons
c. number of protons
d. mass

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

Which best describes why nh4+ can form an ionic bond with ci-?

Suppose that during that icy hot lab 65,000 j of energy were transferred to 450 g of water at 20°c what would have have been the final temperature of the water