Asolution was prepared by mixing 50 μl of 8 mg/ml octadecane internal standard with 100 μl of 12 mg/ml of a dodecane standard with 350 μlhexane. the octadecane peak area was 357 while the dodecane area was 516. calculate the response factor. the same internal standard was used to prepare an unknown sample of dodecane. the sample was prepared by mixing 50 μl of 8 mg/ml octadecane and 100 μl dodecaneof unknown concentration. the areas were 382 for octadecane and 463 for dodecane. calculate the unknownconcentration. remember to use significant figures.

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.

shield volcanos are angry and get mad over the smallest things so much that there heads erupt   pahoehoe and a'a lava. a composite volcano is the poller opposite of a shield volcano. its   peaceful thing and knows how to control its emotions.      

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.