Answer:
Gravity is very important for us,animals and plants. We could not survive Earth without it. The sun's gravity keeps Earth in orbit around it, keeping us a good distance away from it (the sun). Gravity is holding down our atmosphere and the air we need to breathe along with it.
A) c = 3 x 10^8 m/s
f = 7.15 x 10^14 Hz
c = λ x f (=) λ = 3 x 10^8 / 7.15 x 10^14 = 4.19 x 10^-7 m = 419.6 nm
B) E = h f
H = Planck's constant = 6.63 x 10^-34 J/s
E = 6.63 x 10^-34 x 7.15 x 10^14 = 4.74 x 10^-19 J
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Answer:
Answers are explained below
Explanation:
(a)
Oxidation number of iron :
FeO = +2
Fe2O3= +3
Fe3O4 = +2 and +3 since Fe3O4 is the mixture of FeO and Fe2O3.
(b) FeO + CO ----> Fe (s) + CO2
(c) In a pure iron metallic bond is exist between the particles of Fe. But in the form of ore metals forms ionic bond with the non-metals.
Hence the properties vary.
Yes carbon steel has greater strength than that of pure iron but retains the property of iron because no chemical reaction occurs between carbon and iron.
d)
Mixing of carbon in iron is a type of physical change since there is no chemical reactions occur between the carbon and iron. Carbon atoms diffuses in the place between the iron atoms.
(f) One of the property of non-metals are brittleness. It is non ductile .
So when the percentage of carbon increases its atoms also occupying more and more free places.
And increasing the brittleness. So the iron becomes less ductile.
e)
The question is incomplete, the complete question is;
Choose the aqueous solution that has the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable. 0.100 m C6H12O6 0.100 m AlCl3 0.100 m NaCl 0.100 m MgCl2 They all have the same boiling point.
Answer:
AlCl3 0.100 m
Explanation:
Let us remember that the boiling point elevation is given by;
ΔTb = Kb m i
Where;
ΔTb = boiling point elevation
Kb = boiling point constant
m = molality of the solution
i = Van't Hoff factor
We can see from the question that all the solutions possess the same molality, ΔTb now depends on the value of the Van't Hoff factor which in turn depends on the number of particles in solution.
AlCl3 yields four particles in solution, hence ΔTb is highest for AlCl3 . The solution having the highest value of ΔTb also has the highest boiling point.
