Answer:
2.0x10¹⁷ Hz is the frequency of the X-ray
Explanation:
We can find the frequency of a wave of energy from the wavelenght and its speed using the formula:
v = λƒ
<em>Where v is speed (For electromagnetic radiation = 3.0x10⁸m/s)</em>
<em>λ is the wavelength in meters = 1.5x10⁻⁹m</em>
<em>And f is the frequency in s⁻¹ = Hz</em>
<em />
Replacing:
3.0x10⁸m/s = 1.5x10⁻⁹m*ƒ
3.0x10⁸m/s / 1.5x10⁻⁹m = f
f =
<h3>2.0x10¹⁷ Hz is the frequency of the X-ray</h3>
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Well, when an atom attains a stable valence electron, it means that the outer electrons are complete and so cannot attain any more electrons. For the first shell, it is complete when it has 2 electrons, the second shell is complete when it has 8 electrons, all the other shells also have a particular number when complete. Anyway, i believe the answer is HYDROGEN because when HYDROGEN combines with another atom of HYDROGEN, the outer shell is completed. This is because HYDROGEN has only 1 electron. If the two HYDROGENS, which both have 1 electron combine, they make the electrons 2, which is complete for the first shell, HYDROGEN ends in the first shell. Since the electrons become 2, the shell is at stable valence. In all the other options, this happens;
NEON- It has 10 electrons, 2 in the first shell and 8 in the second. So the the shells are already complete, so it can't bond with any thing, which is completely against the question.
RADON- Radon has 86 electrons.
HELIUM- Helium has 2 electrons, so the shell is already full, and cannot bond, so it goes against the question. The question says BY BONDING.
So the answer is definitely 4) HYDROGEN
Hope i helped. Have a nice day, by the way, i'm very sure it's hydrogen.
The concentration of solution in M or mol/L can be calculated using the following formula:
.... (1)
Here, n is number of moles and V is volume of solution in L.
The molecular formula of potassium sulfate is 
thus, there are 2 moles of potassium in 1 mol of potassium sulfate.
1 mol of potassium will be there in 0.5 mol of potassium sulfate.
Mass of potassium is 4.15 g, molar mass is 39.1 g/mol.
Number of moles can be calculated as follows:
Here, m is mass and M is molar mass
Putting the values,
Thus, number of moles of will be 
.
The volume of solution is 225 mL, converting this into L,
Thus,
Putting the values in equation (1),
Therefore, concentration of potassium sulfate solution is 0.236 M.
<u>U</u> <u>VORBELLO</u> <u>FRANÇAIS</u><u>?</u><u>?</u><u>?</u>
Answer:
212.8 dm^3 or L
Explanation:
1 mole of any sub=6.02×10^23 molecules
X mole of O2=5.7×10^24 molecules
X mole=5.7×10^24/6.02×10^23
=9.5 mole
1 mole of any gas at stp=22.4 dm^3
Therefore, 9.5 mole of O2 will be 22.4×9.5
=212.8 dm^3
