Answer:
because they are found freely in nature uncombined so they are highly reactive with other elements
It depends on where the sun is hitting the moon in relation to the earth
Answer:
D. 24 hours, 365 days
Explanation:
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and this is correct answer
Answer:
Explanation:
a ) Entropy change dS = dQ/T
= mcdT /T
Integrating both sides
S₂ - S₁ = - mclnT₂ /T₁
= - .5 X 4200 ln (85+273) /( 20 + 273 )
.5 X 4200 ln 358/ 293
= - 417.6 J/K
Entropy change will be negative as heat is lost by the system .
b ) Sine there is no change in the temperature of air , This heat will enter air at temperature ( 20+ 273) K = 293 K
Heat entering air
= .5 x 4200 x 65
= 136500 J
Change in entropy
136500 / 293 ( room temperature is constant at 293k
= + 465.87 J/K
Entropy change will be positive as heat is gained by the system .
Total change in the entropy of the system (tea + air )
= +465.87 - 417.6
= 48.27 J/K
Entropy change will be negative as heat is lost by the system .
