Which of the following are uses for radiation and radioactivity that are of benefit to us?
i. nuclear waste
ii. radioisotopes
iii. excess exposure

a. i only
b. ii only
c. iii only
d. i and ii only
e. i and iii only

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.

the equation for synthesis of water is as follows;

here two moles of hydrogen are used with one mole of oxygen which gives one molecule of water as a product. but shana misinterpreted 2 moles as 2 grams in this equation.