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Q12.7: NCERT Physics - Part 2 KINETIC THEORY 12.7 Solution: Estimate the average thermal energy of a helium atom at (i)…

Estimate the average thermal energy of a helium atom at (i) room temperature (27 �C), (ii) the temperature on the surface of the Sun (6000 K), (iii) the temperature of 10 million kelvin (the typical core temperature in the case of a star).

Step-by-Step Verified Solution

**Answer:** (i) 6.21×10−216.21 \times 10^{-21} J (ii) 1.24×10−191.24 \times 10^{-19} J (iii) 2.07×10−162.07 \times 10^{-16} J **Step-by-Step Explanation:** Average thermal energy of a monatomic gas atom:
E=32kTE = \frac{3}{2}kT
(i) T=27∘C=300T = 27^\circ\text{C} = 300 K:
E=32×1.38×10−23×300=6.21×10−21 JE = \frac{3}{2} \times 1.38 \times 10^{-23} \times 300 = 6.21 \times 10^{-21} \text{ J}
(ii) T=6000T = 6000 K:
E=32×1.38×10−23×6000=1.24×10−19 JE = \frac{3}{2} \times 1.38 \times 10^{-23} \times 6000 = 1.24 \times 10^{-19} \text{ J}
(iii) T=107T = 10^7 K:
E=32×1.38×10−23×107=2.07×10−16 JE = \frac{3}{2} \times 1.38 \times 10^{-23} \times 10^7 = 2.07 \times 10^{-16} \text{ J}
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All Questions in this Chapter

Q12.1 Q12.2 Q12.3 Q12.4 Q12.5 Q12.6 Q12.7 Q12.8 Q12.9 Q12.10

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