Because the polar regions receive low-angle insolation.
Insolation is the amount of solar radiation received by a given area. The Sun is always low on the horizon. The low Sun angle makes the beam of solar radiation to travel a longer distance from upper troposphere to reach earth's surface as compared to when it is directly overhead. In this case, the radiations are scattered and reflected more by the atmosphere and spread over a larger area. Thus, the intensity of solar radiation is very less at polar regions than near the equatorial region. This is the reason of very cold climates at polar regions.
The electrons contribute just about zero to the mass of an atom.
It takes more than 1,800 electrons to make the mass of one
proton or neutron.
The naturally occurring element with the most complex atom is
Uranium. That's element #92 , so a neutral uranium atom has
92 electrons. It would take almost exactly 20 times that many
electrons to add the mass of one proton or neutron to the atom!
(And no other element has that many electrons in an atom of it.)
Carry capacity determines maximum population size
Answer: The ice absorb 6671.1 kJ of thermal energy.
Explanation:
The conversions involved in this process are :
Now we have to calculate the enthalpy change.
where,
= enthalpy change = ?
m = mass of ice = 20.0 kg = 
(1kg=1000g)
n = number of moles of ice= 
= enthalpy change for fusion = 6.01 KJ/mole = 6010 J/mole
Now put all the given values in the above expression, we get
(1 kJ = 1000 J)
Therefore, the enthalpy change is, 6671.1 kJ
