<u>Answer:</u>
<em>The amount of energy needed when water at 72 degrees c freezes completely at 0 degrees c is 
Joules</em>
<em></em>
<u>Explanation:</u>
where
= Final T - Initial T
=30125J
Q is the heat energy in Joules
c is the specific heat capacity (for water 1.0 cal/(g℃)) or 4.184 J/(g℃)
m is the mass of water
mass of water is assumed as 100 g (since not mentioned)
is the heat energy required for the phase change
=mass × heat of fusion
Total heat = 
Total Heat = 30123J + 33600J
= 63725 J
= Joules is the answer
Answer:
They display the number of valence electrons surrounding an element or compound.
Explanation:
Answer : The correct option is B.
Explanation :
The temperature of the warm water is higher than the cold water. That means as the temperature of warm water increases, the kinetic energy of the warm water molecule also increases.
As the kinetic energy of the warm water molecule increases, the number of molecules conversion into a vapor also increases (i.e, quick evaporation), thereby increasing the vapor pressure of warm water.
Hence, the correct answer is, (B) Warm water evaporates more quickly.
The answer is B. In order to test something out you need to be able to solve it.
Answer:
Explanation:
so u can work out the amount of moles in FeO3 by doing mr of fe3o3 is 55.8*3+16*3=215.4
moles= mass/mr so you do 15.5g/215.4=0.0719 moles
then using 1 to 1 ratio so O2 moles is 0.0719
then use the equation mass=mole*mr
so 0.0719*16=1.15g
hope this make sense :)
