Hello my friend,
No. of valence electron determine the reaction between elements.
hope it helps☺☺
Explanation:
(a) The given data is as follows.
B = 
Z = 4 for Be
Now, for the first excited state 
= 2; and 
if it is ionized.
Therefore, ionization energy will be calculated as follows.
I.E = 
= 
Converting this energy into kJ/mol as follows.
= 5249 kJ/mol
Therefore, the ionization energy of the 
ion in its first excited state in kilojoules per mole is 5249 kJ/mol.
(b) Change in ionization energy is as follows.
= 
or, = 
Therefore, wavelength of light given off from the ion by electrons dropping from the fourth (n = 4) to the second (n = 2) energy levels .
The correct answer for the question that is being presented above is this one: "<span>16.728 g."</span>
Given that
ΔHsolid = -5.66 kJ/mol.
This means that 5.66 kJ of heat is released when 1 mole of NH3 solidifies
When 5.57 kJ of heat is released
amount of NH3 solidifies = 5.57/5.66 = 0.984 moles
<span>molar mass of NH3 = 17 g/mole </span>
<span>1 mole of NH3 = 17 g </span>
So, 0.984 moles of NH3 = 17 X 0.984 = 16.728 g
Arsenic
Arsenic has an atomic mass of 74.92, is a well known poison, and a metalloid.
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