In order to make calcium hydroxide, scientists combine calcium oxide with water according to the reaction below.
Ca0 + 2H2O -> Ca(OH)2

Scientists believe they will need about 4.1x10^22 g of calcium hydroxide to
neutralize some of the carbonic acid to impact the pH, Determine the mass of
calcium oxide needed to produce 4.1x10^22 g of calcium hydroxide in excess
water.

they are both synthetic elements

explanation:

d

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.