True. Nuclear fusion of hydrogen to form helium occurs naturallyin the sun and other stars. It takes place only at extremely high temperatures.
Answer:
wavelength = 0.534×10⁻¹⁶ m
Explanation:
Given data:
Frequency of wave = 5.62 ×10²⁴ Hz
Wavelength = ?
Solution:
Speed of photon = wavelength × frequency
wavelength = speed of photon / frequency
Now we will put the values in formula:
wavelength = 3×10⁸ m/s / 5.62 ×10²⁴ Hz
Hz = s⁻¹
wavelength = 3×10⁸ m/s / 5.62 ×10²⁴ s⁻¹
wavelength = 0.534×10⁻¹⁶ m
Answer:
Highest boiling point - 0.43 m Urea
Second highest boiling point - 0.20 m NiSO4
Third highest boiling point - 0.19 m NH4I
Lowest boiling point - 0.17 m NH4NO3
Explanation:
We know that;
ΔT = kb m i
Where;
ΔT = boiling point elevation
kb = boiling point constant
m = molality of the solution
i = Van't Hoff factor
For NiSO4 , NH4I and NH4NO3 , the Van't Hoff factor, i = 2
But for Urea, the Van't Hoff factor, i = 1
We also have to consider both the values of the molality and Van't Hoff factor , knowing that a higher molality and a higher Van't Hoff factor leads to a higher ΔT and consequently a higher boiling point.
This facts above account for the arrangement of substances shown in the answer.
