The number of grams of radon 222 did it have 15.2 ago was 49.6 grams( answer C)
<u>calculation</u>
- calculate the number of half life it has covered from 15.2 days to 3.8 days
that is divide 15.2/ 3.8 = 4 half life
- half life is time taken for a radio activity of a specified isotope to fall to half its original mass
therefore 3.8 days ago it was 3.1 x2 = 6.2 grams
7.6 days ago it was 6.2 x2 = 12.4 grams
11.4 days ago it was 12.4 x2= 24.8 grams
15.2 days ago it was 24.8 x2=49.6 grams
Answer:
Magnesium hydroxide has 3 unique elements.
Explanation:
Long story short, 2 is the balancing compound in structure to make up hydroxide, therefore 1 compound would be left to create Mg(2O)H.
(This is only an opinion of mathematical science to me, I don't have complete understanding of this subject either, good luck.)
Answer:
3.62moles
Explanation:
First let us generate a balanced equation for the reaction
2Na + Cl2 —> 2NaCl
Molar Mass of Na = 23g/mol
Mass of Na from the balanced equation = 2 x 23 = 46g
Molar Mass of NaCl = 23 + 35.5 = 58.5g/mol
Mass of NaCl from the balanced equation = 2 x 58.5 = 117g
From the question,
46g of Na produced 117g of NaCl.
Therefore, 83g of Na will produce = (83 x 117)/46 = 211.11g of NaCl
Converting this mass (211.11g of NaCl) to mole, we obtain:
n = Mass /Molar Mass
n = 211.11/ 58.5
3.62moles
