<h3>
Answer:</h3>
Lead-205 (Pb-205)
<h3>
Explanation:</h3>
<u>We are given;</u>
We are supposed to identify its product after an alpha decay;
- Polonium-209 has a mass number of 209 and an atomic number of 84.
- When an element undergoes an alpha decay, the mass number decreases by 4 while the atomic number decreases by 2.
- Therefore, when Po-209 undergoes alpha decay it results to the formation of a product with a mass number of 205 and atomic number of 82.
- The product from this decay is Pb-205, because Pb-205 has a mass number of 205 and atomic number 82.
- The equation for the decay is;
²⁰⁹₈₄Po → ²⁰⁵₈₂Pb + ⁴₂He
- Note; An alpha particle is represented by a helium nucleus, ⁴₂He.
Answer:
is the concentration of
in the solution.
Explanation:
![Ni^{2+}(aq) + 3 en\rightleftharpoons [Ni(en)_3]^{2+}(aq)](https://tex.z-dn.net/?f=Ni%5E%7B2%2B%7D%28aq%29%20%2B%203%20en%5Crightleftharpoons%20%5BNi%28en%29_3%5D%5E%7B2%2B%7D%28aq%29)
Concentration of nickel ion = ![[Ni^{2+}]=x](https://tex.z-dn.net/?f=%5BNi%5E%7B2%2B%7D%5D%3Dx)
Concentration of nickel complex= ![[[Ni(en)_3]^{2+}]=\frac{0.16 mol}{2 L}=0.08 mol/L](https://tex.z-dn.net/?f=%5B%5BNi%28en%29_3%5D%5E%7B2%2B%7D%5D%3D%5Cfrac%7B0.16%20mol%7D%7B2%20L%7D%3D0.08%20mol%2FL)
Concentration of ethylenediamine = ![[en]=\frac{0.80 mol}{2 L}=0.40 mol/L](https://tex.z-dn.net/?f=%5Ben%5D%3D%5Cfrac%7B0.80%20mol%7D%7B2%20L%7D%3D0.40%20mol%2FL)
The formation constant of the complex = 
The expression of formation constant is given as:
![K_f=\frac{[[Ni(en)_3]^{2+}]}{[Ni^{2+}][en]^3}](https://tex.z-dn.net/?f=K_f%3D%5Cfrac%7B%5B%5BNi%28en%29_3%5D%5E%7B2%2B%7D%5D%7D%7B%5BNi%5E%7B2%2B%7D%5D%5Ben%5D%5E3%7D)



is the concentration of
in the solution.
Answer:
Objective
Optics
For an optical instrument, the aperture is the diameter of the objective lens (refracting telescope) or the primary mirror (reflecting telescope). The larger the aperture, the more light the telescope can gather, and the fainter the limiting magnitude of the instrument.
Explanation:
Answer:
In general, a scientific law is the description of an observed phenomenon. It doesn't explain why the phenomenon exists or what causes it. The explanation of a phenomenon is called a scientific theory. It is a misconception that theories turn into laws with enough research.
Explanation: