The early atmosphere was probably mostly carbon dioxide, with little or no oxygen. <span>The proportion of oxygen went up because of </span>photosynthesis. The photosynthesis was conducted from <span>tiny organisms.
</span><span>cyanobacteria, or blue-green algae. </span><span>
They </span>used sunshine, water and carbon dioxide to produce carbohydrates and, yes, oxygen. This change to the atmosphere was very important because the <span>breathable air we enjoy today was created.</span>
Answer:
The number of valence electrons in an atom is reflected by its position in the periodic table of the elements (see the periodic table in the Figure below). Across each row, or period, of the periodic table, the number of valence electrons in groups 1–2 and 13–18 increases by one from one element to the next
<u>Answer:</u>
![\Delta E=-1312[\frac{1}{(n_f^2)}-\frac {1}{(n_i^2 )}]KJ mol^{-1}](https://tex.z-dn.net/?f=%5CDelta%20E%3D-1312%5B%5Cfrac%7B1%7D%7B%28n_f%5E2%29%7D-%5Cfrac%20%7B1%7D%7B%28n_i%5E2%20%29%7D%5DKJ%20mol%5E%7B-1%7D)
![\Delta E=-1312[\frac{1}{3^2)}-\frac {1}{(1^2 )}]KJ mol^{-1}](https://tex.z-dn.net/?f=%5CDelta%20E%3D-1312%5B%5Cfrac%7B1%7D%7B3%5E2%29%7D-%5Cfrac%20%7B1%7D%7B%281%5E2%20%29%7D%5DKJ%20mol%5E%7B-1%7D)
![\Delta E=-1312[\frac{1}{(9)}-\frac {1}{(1 )}]KJ mol^{-1}](https://tex.z-dn.net/?f=%5CDelta%20E%3D-1312%5B%5Cfrac%7B1%7D%7B%289%29%7D-%5Cfrac%20%7B1%7D%7B%281%20%29%7D%5DKJ%20mol%5E%7B-1%7D)
![\Delta E=-1312[0.111-1]KJ mol^{-1}](https://tex.z-dn.net/?f=%5CDelta%20E%3D-1312%5B0.111-1%5DKJ%20mol%5E%7B-1%7D)
h is planck's constant
c is the speed of light
λ is the wavelength of light
Wavelength
<em>Thus, the wavelength of light associated with the transition from n=1 to n=3 in the hydrogen atom is </em><u><em>103 nm.</em></u>
Answer:
he pH of a solution is defined as the negative log10 [H+] ... 1 x 10-11. 11. Acidic Solution. 1 x 10-4. 4. 1 x 10-10. 10. 1 x 10-5. 5. 1 x 10-9.
Explanation:
m
