A simple coffee-cup calorimeter is often used to determine the amount of heated released when an acid is neutralized by a base. When 90.0 g of 3.00 M hydrochloric acid (HCl) is neutralized with 90.0 g of 3.00 M sodium hydroxide (NaOH), the temperature of the solution increases from 22.0 oC to 42.0 oC. Using a specific heat capacity of the mixture of 4.2 J/g. oC, how much heat in kJ is released in this reaction, assuming the calorimeter does not absorb any heat and that there is no heat exchange between the calorimeter and the surrounding air.

can you attach a picture of the lettuce? : )

it's all four options.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.

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.