What is the mass in grams of 9.76 × 1012 atoms of naturally occurring beryllium?

The atomic mass of beryllium (Be) is 9 g/mole

Now, 1 mole of any substance contains avogadro's number of that substance. Therefore:

1 mole of Be contains 6.023  10^23 atoms of Be

In other words:

9 grams of Be contains 6.023*10^23 atoms of Be

Therefore, the mass corresponding to 9.76 * 10^12 atoms of Be is:

= 9 g * 9.76 10^12 atoms/6.023*10^23 atoms

= 1.458 * 10^-10 g (or) 1.46 * 10^-10 g

the answer would be b i believe

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.