We can find the principal level or lower level
using Rydberg's formula:
1/w = R(1/L² - 1/U²)
<span>where:</span>
<span>w is the
wavelength (93.8 nm),</span>
L is the lower energy level (unknown)
U the upper energy level (n= 6)
R is Rydberg's constant (10,967,758
waves per meter)
Substituing known values into the equation:<span>
1/(9.38 * 10^-8 m.) = 10,967,758(1/L² - 1-36) </span>
Using the solver function of the calculator to
get for L:
L = 0.999 <span>
so L = 1.
<span>The lower level is 1 (the ground state).</span></span>
Answer:
C. 30.0 g NaOH and add water until the final solution has a volume of 3.00 L.
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
from the question ,
M = 0.250M
V = 3.00 L
M = n / V
n = M * v
n = 0.250M * 3.00 L = 0.75 mol
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
n = 0.75 mol NaOH
m = molecular mass of NaOH = 40 g/mol
n = w / m
w = n * m
w = 0.75 mol * 40 g/mol = 30.0 g
Hence , by using 30.0 g of NaOH and dissolving it to make up the volume to 3 L , a solution of 0.250 M can be prepared .
The periodic table is an ordered way of representing chemical elements. They were ordered according to their atomic number, remember that the atomic number corresponds to the number of protons of the elements.
So the answer will be option C) Atomic Number
