11. The two methods commonly used for producing sulfuric acid are called the lead-chamber method and the contact process method. The lead-chamber method is inexpensive and has a percentage yield of
about 70%. The contact process is a newer and more expensive method. In this method, 100.0 kg of
SO2 (sulfur dioxide) will generally produce 150.0 kg of H2SO4 (sulfuric acid). The theoretical yield for
this reaction is 153 kg of H2SO4
What is the percentage yield for the contact process?
a. 33.0 %
b. 66.7 %
C. 98.0 %
d, 102 %

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.

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.