Answer:
Oxygen.
Explanation:
Hello,
Yeast fermentation in the food industry must be carried out under anaerobic conditions as long as when oxygen is present respiration occurs rather than fermentation.
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Answer:
the systematic name is called Lithium sulfide.
Answer:
Explanation:
Niels Bohr was a Danish physicist who proposed the hydrogen atom quantum model to explain the discontinuity of the atom's emission spectra.
In <em>Bohr hydrogen atom</em> model, the electrons occupy orbits identified with the numbers <em>n = 1, 2, 3, 4</em>, ... Each number (orbit) corresponds to a different energy level or state. The number n = 1 corresponds to the lowest energy level, and each higher number corresponds to a higher energy level.
This table shows the relative energy of the different orbits of the <em>Bhor hydrogen atom</em><em>:</em>
Orbit Quantum Energy Relative
number level energy
First n = 1 1 E₁
Second n = 2 2 2E₁
Third n = 3 3 9E₁
Fourth n = 4 4 16E₁
Fifth n = 5 5 25E₁
Sixth n = 6 6 36E₁
Seventh n = 7 7 49E₁
When an electron jumps from a higher energy state down to a lower energy state, it emits a photon with an energy equal to the difference of the energies between the initial and the final states.
Since the <u>n = 6 to n = 1</u> transition results in the higher relative energy difference (36E₁ - E₁ = 35E₁), you conclude that it is this transition which results in <u><em>the emission of the highest-energy photon,</em></u><em> which is the option A. </em>
Answer:
274.5g of CCl₂F₂
Explanation:
To freeze 200g of water yo need to decrease the temperature of water from 15°C to 0°C and then change its phase from solid to liquid. That is:
Decreasing temperature:
q = 4.18J/gK ×200g× (15°C - 0°C)
q = 12540J
In the change of phase:
q = 334 J/g × 200g
q = 66800J
Thus, total heat is:
12540J + 66800J = <em>79340J</em>.
If this heat comes from CCl₂F₂ vaporization, must be evaporated:
79340J × (1g / 289J) = <em>274.5g of CCl₂F₂</em>
