Answer:
amu = 34.055 or 34.1
Explanation:
to calculate the average mass, first convert the percentages into decimals. Then, calculate the mass numbers. To get this number, multiply the decimal by the mass number for each isotope and, then add them together.
( 0.315 x 32 ) + (0.685 x 35 ) = 34.055
Blue light is emitted when an electron in a He+ ion falls from the energy level n=4 to n=1. This is because the energy difference between these levels is similar to that in a hydrogen atom when blue light is emitted (from n=5 to n=2).
The energy of the emitted photon when an electron transitions between energy levels in an atom is determined by the difference between the energy levels it transitions between. This is described by the formula: E = hν, where E stands for energy, h stands for Planck's constant, and ν stands for frequency. The color of the emitted light, or the wavelength, is determined by the energy of the photon.
For blue light to be emitted when an excited electron falls from n=4 in a He+ ion, it must fall into n=1. This is because the energy gap between the n=4 and n=1 levels in a He+ ion is similar to that between the n=5 and n=2 levels in a hydrogen atom, which results in the emission of blue light.
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In a helium ion (He+), an electron would need to fall from n=4 to n=1 to emit a photon of blue light, similar to the photon emitted when an electron in a hydrogen atom falls from n=5 to n=2.
According to the Bohr model of atoms, when an electron falls from a higher to a lower energy level, a photon is emitted. The energy (and therefore color) of the photon corresponds to the energy difference between the two energy levels. In the case of your question, an excited electron in a hydrogen atom falls from n=5 to n=2 and emits a photon of blue light.
If an electron in an excited helium ion (He+) falls from the n=4 level, to emit a photon of similar energy (and thus color), it must fall to a level that yields a similar energy difference. Based on the energy levels of helium and hydrogen, the electron in the He+ ion would need to fall to n=1 to emit a photon of similar energy to the blue light from the hydrogen atom, given that the energy difference in He+ ion is larger than in hydrogen atom for the same quantum numbers due to its greater nuclear charge.
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exothermic reactions absorb heat and endothermic reactions give off heat
endothermic and exothermic reactions absorb heat
endothermic and exothermic reactions give off heat
The Ksp Expression for the given solid in molar solubility terms is; Ksp = 4x³
Ksp is simply defined as solubility product constant and it is the equilibrium expression for the dissolving of a solid.
Now, the solid ab₂ dissolved as shown in the formula;
ab₂(s) → a(aq) + 2b(aq)
Thus, the equilibrium constant is;
Ksp = ([a][b]²)/[ab₂]
Now, since the solids are not put into the equation as a result of not having enough concentration, it can be simplified to;
Ksp = [a][b]².
Now, Molar solubility another term for molarity and as such it means we will say; x = a
Since b = 2x, there is twice the amount of b than a and as such we can write a and b in terms of x to get;
Ksp = [x][2x]² = 4x³
Read more about Molar Solubility at; brainly.com/question/9732001