What is the concentration (% m/v) of the solution that contains 20.0 g NaCl in 800.0 mL solution? a. 5.00%
b.2.50%
c. 0.20%
d. 2.00%

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

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.

what is the question?