A liquid sample has a reported volume of 810 mL. A. What is the implied +/- error of this measurement? And, identify the certain digits and the uncertain digits in the measurement.

B. If the volume was instead able to be reported as 810. mL, what would be the implied +/-error? And, identify the certain and uncertain digits.

C. Which of the two volumes 810 mL or 810. mL is more precise? What would have to change to allow the reported volume to be written as 810. mL instead of 810 mL?

with this one i know the answer in craters one reason i looked it up and i learned about it there is my evidence

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.

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.      

c. electrical charges of ionic bonds.