An alloy maybe could be used as a solid but i really don't think that would be it so i would sayether from an alloy or dirt
Oxygen gas was most likely absent from Earth's primitive atmosphere. The current theory is that the Earth's early atmosphere was composed of mainly carbon dioxide and methane due to the high volcanic activity. Cyanobacteria and their use of photosynthesis was what caused earth's atmosphere to become oxygen enriched.
I hope that helps.
Answer:
Energy per mole of photons = 2.31 × 10^2 KJ/mol
Explanation:
Energy, E = hf;
Where h is Planck's constant = 6.63 ×10^-34, and f is frequency of the photons.
E = 6.63 × 10^-34 × 5.8 × 10^14
E = 3.84 × 10^-22 KiloJoules
I mole of photons contains Avogadro's number of particles, 6.02 × 10^23
Therefore, the energy per mile of photon is 3.84 × 10^-22 KJ × 6.02 × 10^23
Energy per mile of photon = 2.31 × 10^2 KJ/mol
Answer:
B) K⁺, Sr²⁺ , O²⁻
Explanation:
Potassium is present in group one. It is alkali metal and have one valance electron.Potassium need to lose its one valance electron and form cation to get complete octet.
That's why it shows K⁺.
Sr is alkaline earth metal. It is present in group two. It has two valance electrons. Strontium needed to lose its two valance electrons and get stable electronic configuration.
When it loses its two valance electrons it shows cation with charge of +2.
Sr²⁺
Oxygen is present in group 16. It has sex valance electrons. It needed two more electrons to complete the octet. That's why oxygen gain two electron and form anion with a charge of -2.
O²⁻