<span>Ultra violet light is the catalyst that converts 7-dehydrocholesterol to provitamin D3. Ultra violet light can be obtained from the sun. The conversion happens when UVB light hits the skin (where 7-dehydrocholesterol naturally resides), gets absorbed, and us metabolized inside of the body.</span>
Explanation:
As the Earth moves around the sun during a year, the northern half of the Earth is tilted towards the sun in the summer, making daytime longer than night. In winter, this reverses; the earth tilts away from the sun and nighttime becomes longer
Answer:
709415.584 g
Explanation:
This is a heat capacity problem. We use the formula below to calculate.
Q=mcΔT
where Q is the quantity of heat
m is the mass of substance
ΔT is the change in temperature of substance( T2-T1).
Q= 9.5MJ = 9.5*10^(6}J
C.P = 30.8J/(K.mol)
temperature of sodium increases by 10°C which means our final temperature in kelvin T2 will be 510K
initial temperature T1= 500K
m= Q/[c (T2-T1)]
m= 9.5*10^(6}/ {30.8(510-500)]
m= 30844.156 mol of Na
Converting to grams we multiply by the molar mass of Na.
molar mass of Na = 23
mass of Na= 30844.156 *23
=709415.584 g
