They are isotopes because isotopes have the same number of protons (atomic number) but can have different numbers of neutrons + protons (atomic mass).
“Water” is the best thermal insulator.
Option: B
<u>Explanation</u>:
“Thermal insulators” are the materials which do not allow heat to transfer. “Water” is the substance which does not transfer heat. Hence, the “water” is the best “thermal insulator”. Water is the bad conductor of thermal heat. Water has “low thermal conductivity” than other substances, so this acts as an insulator as long as it is not traveled from one place to another. Heat is transferred when a “hot object collides” with “the cold objects”. The “thermal conductivity” of “water” is 0.6 W/m K.
The 410 mm wavelength corresponds to the n=6 to n=2 transition, the 434
mm wavelength corresponds to the n=5 to n=2 transition.
Planck's equation: E=hc/wavelength
n=6 to n=2 corresponds to a higher energy transition and hence shorter wavelength, 410nm.
We are given with two set of conditions. To calculate the final volume, we get first the number of moles under the first condition. Using PV=nRT, the number of moles is equal to 0.16 moles. We substitute this together with the other conditions in PV=nRT, the final volume is 0.92 liters.