72 percent is hydrogen. Nuclear fusion converts hydrogen into other elements. The sun is also composed of about 26 percent helium and trace amounts of other elements; oxygen, carbon, neon, nitrogen, magnesium, iron and silicon.
http://www.space.com/17170-what-is-the-sun-made-of.html
Density = 7.90 g/cm³
volume = 1.00 cm³
Therefore:
mass = density * volume
mass = 7.90 * 1.00
mass = 7.90 g
Answer:
Explanation:
Because unlike ionic bonds (metal and a non-metal) where electrons are "stolen", covalent bonds are defined by the sharing of electrons between non-metals.
Due to erosion, the soil is taken away from one place to another.This decreases the fertility of the land,.. it also is a cause for floods. Due to erosion, the vegetation is destroyed and nothing can be cultivated for a higher yield in the rough sandy land . Due to weathering of rocks, there is an advantage. The advantage is that the weathering of volcanic rocks give rise to Black Soil by which special crops like cotton,tobacco and sugarcane can be cultivated. Due to weathering, a hilly range may turn into a plain land after thousands of years.
Answer:
D) 5.5 g Fe₂S₃.
Explanation:
- The balanced chemical reaction is: 16Fe(s) + 3S₈(s) → 8Fe₂S₃(s)
- It is clear that 16.0 mole of Fe reacts completely with 3.0 moles of S₈ to produce 8.0 moles of Fe₂S₃.
- We need to calculate the no. of moles of the reacted Fe filings (3.0 g) and yellow sulfur solid (2.5 g).
No. of moles of Fe filings (3.0 g) = mass /atomic mass = (3.0 g) / (55.845 g/mol) = 0.0537 mol.
No. of moles of yellow sulfur solid (2.5 g) = mass / molar mass = (2.5 g) / (256.52 g/mol) = 0.009746 mol.
- We need to determine the limiting reactant,
The theoretical ratio of (Fe: S₈) is (16: 3) which is 5.333.
The actual ratio of the reactants (Fe:S₈) is (0.0537 mol: 0.009746 mol) which is 5.5.
- This means that Fe is found with a slight increase and S₈ is the limiting reactant.
- Now, we can calculate the no. of moles of produced Fe₂S₃;
<u><em>Using cross multiplication:</em></u>
3.0 moles of S₈ produces<em><u> </u></em>→ 8.0 moles of Fe₂S₃, from the stichiometry,
0.009746 moles of S₈ produces → ??? moles of Fe₂S₃.
- The no. of moles of the produced Fe₂S₃ = (8.0 mol)(0.009746 mol) / (3.0 mol) = 0.026 mol.
- Finally, we can get the mass of the the produced Fe₂S₃.
The mass of the the produced Fe₂S₃ = no. of moles x molar mass = (0.026 mol)(207.9 g/mol) = 5.405 g ≅ 5.5 g.