<u>Given data</u>
Determine Internal energy of gas N₂, (U) = ?
Temperature (T) = 25° C
= 25+273 = 298 K,
Gas constant (R) = 8.31 J/ mol-K ,
Number of moles (n) = 3 moles,
<u>Internal energy of N₂ </u>
Internal energy is a property of thermodynamics, the concept of internal energy can be understand by ideal gas. For example N₂, the observations for oxygen and nitrogen at atmospheric temperatures, f=5, (where f is translational degrees of freedom).
So per kilogram of gas,
The internal energy (U) = 5/2 .n.R.T
= (5/2) × 3 × 8.31 ×298
= 18572.85 J
<em>The internal energy of the N₂ is 18,572.85 J and it is approximately equal to 18,600 J given in the option B.</em>
Democritus was the one who did not have experimental evidence to support his theory of the atom.
Answer: Option 4
<u>Explanation:
</u>
The discovery of atoms were first stated by Democritus but due to the absence of any experimental proof, his statement was not noted as significant at that time.
After this, Dalton made the specific assumptions formulating some postulates for the atomic theory with proof. Then the cathode rays tube experiments performed by Thomson lead to the formation of plum pudding models of atom.
This is followed by Rutherford’s gold foil experiment discovering the presence of nucleus inside the atoms. So, Democritus first stated but due to absence of experimental evidences, his theory of atoms were not supported at that time.
Wave speed = (wavelength) x (frequency)
Wave speed = (3 m) x (15 Hz)
<em>Wave speed = 45 m/s</em>
Here is your answer
We know that
Velocity = Frequency × Wavelength
Here,
Frequency = 100Hz
Wavelength= .30m
So,
Velocity= 100× 0.30 m/s
v= 30 m/s
HOPE IT IS USEFUL
