Read the following passage and identify at least two physical and two chemical
properties of zeolites.
Zeolites are crystalline solids composed of silicon, aluminum, and oxygen with
very porous structures. They are very useful in a variety of applications.
Zeolites are formed naturally when volcanic rocks and ash react with alkaline
groundwater. They may also be synthesized in the laboratory by allowing
aluminosilicate crystals to form around small organic molecules. Zeolites
generally have very low density due to their porous nature. They are often
used as molecular sieves because they have large pores that can trap molecules
of certain sizes and shapes while excluding others. Bandages used by the
military sometimes contain zeolites, which absorb water from the blood, thus
accelerating the natural clotting process. Zeolites have also replaced
phosphates in many detergents, which is an ecological benefit because zeolites
do not encourage the growth of algae. Interestingly, the name zeolite comes
from the fact that zeolites give off water in the form of steam when they are
heated; thus, they are called boiling (zeo) stones (lithos).
