250 --> 125 --> 62.5 --> 31.25
each arrow equals one half life, so 3 half lives
14 days/ 3 half lives =
4.67 days = half life
B) 40%
The balanced equation indicates that for every 3 moles of H2 used, 2 moles of NH3 will be produced. So the reaction if it had 100% yield would produce (2.00 / 3) * 2 = 1.333333333 moles of NH3. But only 0.54 moles were produced. So the percent yield is 0.54 / 1.3333 = 0.405 = 40.5%. This is a close enough match to option "b" to be considered correct.
The amount of electrons is based on the proton number
Diamond is an allotrope of carbon; that just means it is a different crystalline structure, but pure diamond contains only carbon atoms. (unrelated, but interesting - colored diamonds come from impurities like boron and nitrogen in the crystal structure!) The molar mass of carbon is 12.01 g/mol. You can find the molar mass by looking at the periodic table. If you look under number 6, Carbon, you should see the atomic weight right under it: 12.01. The molar mass is this same number, in grams. That means that one mole, or 6.022E23 carbon atoms, weigh 12.01 grams.
<span>But you don't have one mole. You only have 2 grams. </span>
<span>So how many moles do you have? 2 grams out of 12 grams. 2/12 = 1/6 or 0.167. You have 1/6th of a mole. One mole is 6.022E23 atoms, but you only have 1/6th of that. I hope that thinking about it stepwise like this makes sense to you. It works the same for other atoms and molecules too. In a molecule, you would just add up the molar mass of all the component atoms. I hope this helps.
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ANSWER:
all of them
Explanation:
preciseness is measured by how many decimal places are used not by accuracy. since all of these are to the same decimal place they are all equally precise even if they are inaccurate.
