Select the correct answer. Marissa is testing a hypothesis through experimentation. She believes that immersing ocean coral in carbonic acid will slow the coral’s growth. Which of these actions will prevent Marissa from introducing confounding variables into her experiment? A. She releases cement particles into a random number of the coral samples. B. She uses three different types of coral to establish her dependent variables. C. She treats the coral samples identically with varying levels of carbonic acid. D. She obtains her coral samples from coral reefs surrounding different continents.

the correct answer is:

a. formation of precipitation

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

the correct answer would be b) volume versus temperature, because they are also directly proportional.

it was spontaneous.

"ain't i a woman? " is the name given to a speech, delivered extemporaneously, by sojourner truth, (1797–1883), born into slavery in new york state.sojourner truth' delivered her famous speech "ain't i a woman? " (which did not have a title at that moment) was given without any previous preparation. her dissertation took place at the women's convention in akron, ohio, in 1851.