Answer:
Answer is c the moon passes in between the sun and the earth.
Explanation:
I hope this helps.
Answer:
C. If farmers do not use soil conservation practices, the topsoil, which contains humus, will not be fertile to promote plant growth because of the loss of nutrients from the soil.
Explanation:
The top soil is rich in humus and not weathered materials. It is not close to the bedrock. Rather, the topsoil is rich in organic matter and it is present as humus in the soil.
- If crop rotation is not being practiced, the soil's nutrients would be highly depleted without replenishing them back.
- With crop rotation the top soil can be made more fertile when it is left uncultivated for a period of time.
- Instead of heavily relying on a single piece of land, crops can rotated on a timed basis so that soils will have enough time to restore their nutrients.
Answer:- solution boiling point = 102.23 degree C (102 degree C with three sig figs).
Solution:- When a non volatile solute is added to a solvent then boiling point increases. Elevation in boiling point is directly proportional to the molality of the solution.
The equation is:
where, 
is the elevation in boiling point, i is the Van't hoff factor, 
is the molal elevation constant and m is the molality.
Value of i is 1 as ethylene glycol is a covalent molecule that does not break to give ions. for water is 
.
We can calculate the molality from the given grams of ethylene glycol and liters of water as molality is moles of solute per kg of solvent.
Molar mass of ethylene glycol is 62 gram per mol and density of water is 1.00 kg per liter.
= 2.50 kg
Let's calculate the moles of ethylene glycol.
= 10.9 mol
molality of the solution = 
= 4.36m
Let's plug in the values in the equation we have on the top for elevation in boiling point.
= 
Boiling point of pure water is 100 degree C. So, the boiling point of the solution = 100 + 2.23 = 102.23 degree C
(If we fix the three sig figs then it could be written as 102 degree C.)
If the element have 39 protons, that means that his atomic number is 39, being Yttrium the element. And, the number of protons is the same of the number of electrons, so, 39 electrons.
Answer:
Mass of Fe produced = 3.86785211069 ≈ 3.87 kg
Explanation:
From the question the chemical reaction can be written as follow :
Fe2O3 + C → Fe + CO
Balance the equation
Fe2O3 + 3C → 2Fe + 3CO
compute the molecular mass of Fe2O3 and atomic mass of Iron(Fe)
Molecular mass of Fe2O3 = 55.845(2) + 15.999(3) = 111.69 + 47.997 = 159.687 g
Atomic mass of iron = 55.845 g
From the balanced equation
159.687 g of Fe2O3 produces 2 × 55.845 = 111.69 g of Fe(iron)
Convert the 5.53 kg to gram
1 kg = 1000 g
5.53 kg = 5.53 × 1000 = 5530 g
since,
159.687 g of Fe2O3 produces 2 × 55.845 = 111.69 g of Iron(Fe)
5530 g of Fe2O3 will produce
cross multiply
Mass of Fe produced =5530 × 111.69/159.687
Mass of Fe produced = 617645.7
/159.687
Mass of Fe produced = 3867.85211069 g
convert to kg
1000 g = 1 kg
3867.85211069 = 3867.85211069/1000
Mass of Fe produced = 3.86785211069 ≈ 3.87 kg
