It is called a hypothesis
Answer:
E = 15×10⁻²⁹ J
Explanation:
Given data:
Frequency of photon = 2.2× 10⁷ Hz
Energy of photon = ?
Solution:
Formula:
E = h.f
h = 6.63×10⁻³⁴ Js
by putting values,
E = 6.63×10⁻³⁴ Js × 2.2× 10⁷ s⁻¹
E = 14.586 ×10⁻²⁹ J
E = 15×10⁻²⁹ J
The energy of photon is 15×10⁻²⁹ J.
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100 billion planets are in our galaxy.
About 60 billion planets are inhabitable by humans.
Hope this helps!
Answer: final temperatures will be
a) water 21 C
b) concrete 20.005 C
c) steel 20.008 C
d) mercury 53 C
Explanation:
Change in temp dT = dH / (mass x specific heat)
Specific heat of these materials can be found from many sources:
water = 1 kcal / kg C
concrete = 210 kcal / kg C
steel = 114 kcal / kg C
mercury = 0.03 kcal /kg C
So dT (water) from 1 kcal heat into 1 kg water = 1 kcal / (1 kg x 1 kcal/kg C) = 1 C therefore the final temperature is 20 + 1 = 21 C
But dT (steel) = 1 kcal / (1kg x 114 kcal/kg C) = 0.008 C so the final temperature is 20 + 0.008 = 20.008 C
The results for concrete and mercury are calculated in the same way
It's only a small difference (103 degrees versus 104 degrees in water),
and I believe the usual rationalization is that since F is more
electronegative than H, the electrons in the O-F bond spend more time
away from the O (and close to the F) than the electrons in the O-H bond.
That shifts the effective center of the repulsive force between the
bonding pairs away from the O, and hence away from each other. So the
repulsion between the bonding pairs is slightly less, while the
repulsion between the lone pairs on the O is the same -- the result is
the angle between the bonds is a little less.
Hope this helps!
