Answer:
They give off their own light energy
Explanation:
I'm taking astronomy and I answered this questions not too long ago
Answer:
Fluorine
Explanation:
Fluorine is the most electronegative element because it has 5 electrons in it's 2P shell.
Answer: 1.99 mol h20
Explanation:
you have 36.030 g, trying to get it into mols
to get from g to mols, use the molar mass (periodic table)
36.030 g h20 (1 mol/18.02g) = 1.99 mol h20
Answer : The internal energy change is, -506.3 kJ/mol
Explanation :
Formula used :

or,

where,
= change in enthalpy = 
= change in internal energy = ?
= change in moles
Change in moles = Number of moles of product side - Number of moles of reactant side
According to the reaction:
Change in moles = 0 - 2 = -2 mole
That means, value of
= 0
R = gas constant = 8.314 J/mol.K
T = temperature = 
Now put all the given values in the above formula, we get




Therefore, the internal energy change is -506.3 kJ/mol