Answer:
4.55 m
Explanation:
Given data
- Frequency (ν): 66.0 MHz = 66.0 × 10⁶ Hz = 66.0 × 10⁶ s⁻¹
- Speed of light (c): 3.00 × 10⁸ m/s
We can determine the wavelength of the radio waves using the following expression.
c = λ × ν
λ = c/ν
λ = (3.00 × 10⁸ m/s)/66.0 × 10⁶ s⁻¹
λ = 4.55 m
The wavelength of the radio waves is 4.55 m.
<u>Answer:</u> The given sample of water is not safe for drinking.
<u>Explanation:</u>
We are given:
Concentration of fluorine in water recommended = 4.00 ppm
ppm is the amount of solute (in milligrams) present in kilogram of a solvent. It is also known as parts-per million.
To calculate the ppm of fluorine in water, we use the equation:
Both the masses are in grams.
We are given:
Mass of fluorine = (Conversion factor: 1 g = 1000 mg)
Mass of water = 5.00 g
Putting values in above equation, we get:
As, the calculated concentration is greater than the recommended concentration. So, the given sample of water is not safe for drinking.
Hence, the given sample of water is not safe for drinking.
Answer:
C. The lowest-energy electron configuration of an atom has the maximum number of unpaired electrons, all of which have the same spin, in degenerate orbitals.
Explanation:
The Hund's rule is used to place the electrons in the orbitals is it states that:
1. Every orbital in a sublevel is singly occupied before any orbital is doubly occupied;
2. All of the electrons in singly occupied orbitals have the same spin.
So, the electrons first seek to fill the orbitals with the same energy (degenerate orbitals) before paring with electrons in a half-filled orbital. Orbitals doubly occupied have greater energy, so the lowest-energy electron configuration of an atom has the maximum number of unpaired electrons, and for the second statement, they have the same spin.
The other alternatives are correct, but they're not observed by the Hund's rule.
There are 1.22 grams of He in the mixture. The mixture contains 0.304 moles of He, 0.250 moles of N2 and 0.250 moles of O2. Since the mixture of gases are at standard temperature and pressure, the total moles of the mixture equivalent to 18.0 L is 0.804 moles.
Further Explanation:
At standard temperature and pressure of 0°C and 1.00 atm, the molar volume of gas is 22.4 L.
From this, the total moles of the mixture can be derived using the solution below:
Therefore, the total moles of gases in an 18.0 L mixture at STP is:
By algebra, the moles of He may be solved using the given moles of the other two gases: 0.250 mol N2 and 0.250 mol O2.
0.304 moles of He is equal to 1.22 grams of He.
Learn More:
- Learn more about Boyle's Law brainly.com/question/12968820
- Learn more about Gay-Lussac's Law brainly.com/question/6534668
- Learn more about Ideal Gas Law brainly.com/question/12935899
Keywords: molar volume, STP, stoichiometry
Answer:
Power plants that produce electricity emit at least two-thirds of all sulfur dioxide and more than one-third of all nitrogen oxides that pollute the air.
Hope this helps :)