There are 3 sig figs. 8 and 2 are obvious. The ending 0 is significant because it is at the end of a decimal number, and doesn't have to be measured.
First convert volume to mass:
mass = 0.789 g/mL * 155 mL = 122.295 g
Then convert mass to number of moles:
number of moles = 122.295 g * (1 mole / 46 g) = 2.66 moles
Using avogadros number, we get the molecules:
<span>number of molecules = 2.66 moles * 6.022 x 10^23 molecules
/ mole = 1.6 x 10^24 molecules</span>
There is no image , so you cannot answer , sorry
Answer:
The octet rule means that atoms need a total of 8 valence electrons to fill their valence shell. Hydrogen only needs two to fill its valence shell.
Explanation:
All atoms except for hydrogen can hold a total of 8 valence electrons in their outer energy levels (2 in the s level, 6 in the p level). Hydrogen only has two electrons total, so it does not require more than the s level and two electrons to have a full valence.
