<span> Ksp = [Ba2+][CO32-] = (9.0 X 10⁻⁵)² = 8.1 X 10</span>⁻⁹
If you go by the decimal there should be 5 significant digits because 0 is a trailing zero and matters since it comes after a decimal. however if you do
6.3590 x 10 ^7 = 63590000 then you would only have 4 significant digits because there is no longer a decimal to make the zero after the 9, significant.
Hope this helps!
For the second one it is physical
Answer:
hydrogen atom when it drops from N 5 to N 2?
so, 275 kJ of energy is released when one mole of electrons "falls" from n = 5 to n = 2. E = hc/λ (this energy corresponds to the energy of one photon; the energy calculated in this problem is for one mole of photons so we will change this after we change the units from kJ to J)
Explanation:
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