Answer:
Explanation:
When an electron jumps from one energy level to a lower energy level some energy is released in the form of a photon.
The difference in energy between the two levels is the energy of the photon and that energy is related to the frequency of the photon by the Einstein - Planck equation:
Where,
- E = energy of the photon,
- h = 6.626×10⁻³⁴ J.s, Planck constant, and
- ν = frequency of the photon.
So, to find the frequency you must first find the energy.
The transition energy can be calculated using the formula:
Where E₀ = 13.6 eV ( 1 eV = 1.602×10⁻¹⁹ Joules) and n = 1,2,3,...
So, the transition energy between n = 4 and n = 3 will be:
- ΔE = - E₀ [ 1/4² - 1/3²] = - 13.6 eV [1/16 - 1/9] = 0.6611. . .eV
- ΔE = 1.602×10⁻¹⁹ Joules/eV × 0.6611... eV = 1.0591 ×10⁻¹⁹ Joules
Now you can use the Einstein - Planck equation:
- ν = 1.0591 ×10⁻¹⁹ J / 6.626×10⁻³⁴ J.s = 1.60×10¹⁴ s⁻¹ (rounded to 3 significant figures).
Answer:
Its D. bring a timer to the presentation to keep on time
Explanation:
Presentations don't have to be timed, and usually aren't.
When presenting, you need to talk at a normal speed, otherwise people won't understand what you are saying because your talking so fast.
Not to mention some presentations are long, some are short. It really doesn't matter. Hope this helps!
1. Yes because the ocean takes in the carbon dioxide from the air. This causes more acid in the water, this makes it hard to make shells and skeletons for the seal life that need them.
2.No because it isn't harmful unless it builds up. But there is people who work to clean and limit the chances of build-up.
Hope this helps :)
Carbon 12 (the most common) has 6 protons and 6 neutrons
<span>Carbon 13 has 6 protons an 7 neutrons </span>
<span>Carbon 14 has 6 protons and 8 neutrons and is radioactive</span>
A producer gets it's matter from it's surroundings. E.g a plant will get minerals and water from the ground through it's roots for photosynthesis.
Plants can also produce food by using the sun's light for photolysis of the water molecules. (Basically splitting the H20 into Hydrogen and O2 (oxygen gas). They release oxygen back into the air and combine the Hydrogen ion with carbon dioxide that they obtained from the air to create sugar (glucose) which is basically chemical food for the plants. This is the summed up process of photosynthesis.