Answer : The energy released by an electron in a mercury atom to produce a photon of this light must be, 
Explanation : Given,
Wavelength = 
conversion used : 
Formula used :

As, 
So, 
where,
= frequency
h = Planck's constant = 
= wavelength = 
c = speed of light = 
Now put all the given values in the above formula, we get:


Therefore, the energy released by an electron in a mercury atom to produce a photon of this light must be, 
Answer:
Oxygen and Carbon are in the non-metal section. Both are in 2nd period while Carbon is in group 4A and Oxygen is in group 6A.
Oxygen has more valence electrons than carbon. I wish I could give you a more accurate explanation why on paper, but all you need to do is count the electrons on the largest shell.
Here's the orbital notation of Carbon: 1s^2 2s^2 2px^1 py^1
Carbon's largest shell is 2. Count the electrons on shell 2, and you get 4 valence electrons.
Orbital notation of Oxygen: 1s^2 2s^2 2px^2 py^1 pz^1
Oxygen's largest shell is 2. So, like with carbon, count the electrons on the largest shell. You get 6.
There is a way easier way of interpreting this where you do not even have to write the orbital notation. I wish I can explain, but just know the periods and the group numbers.
<span>Scientists use-
Hardness</span>
<span />Streak
Density
Specific Gravity
ColorCrystal Shape.LusterCleavage/Fracture
Answer:
D. 5.0
Explanation:
Step 1: Write the balanced equation at equilibrium
2 NO₂(g) ⇄ N₂O₄(g)
Step 2: Calculate the concentration equilibrium constant
The concentration equilibrium constant (Kc) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients.
Kc = [N₂O₄]/[NO₂]² = 0.2 / 0.2² = 5