Answer:
It is true that earth was once covered with oceans and little dry land.
Explanation:
Over the course of around four billion years, the Earth's oceans have lost about a quarter of their original mass. Today the atmosphere is rich in oxygen, which reacts with both hydrogen and deuterium to recreate water, which falls back to the Earth's surface. So the vast bulk of the water on Earth is held in a closed system that prevents the planet from gradually drying out. According to the researchers, the continents emerged relatively suddenly from an ocean that covered 95 percent of the Earth's surface. The appearance of large masses of dry land would have caused more extreme weather, changes in ocean currents and the emergence of proper seasons. In turn, these environmental changes may have led to rise in atmospheric oxygen that enabled the explosion of new life forms around 500 million years ago.
I think the correct answer from the choices listed above is option B. It would be a leaf changing color in autumn <span>would a chemist be most likely to study. A chemist should be more interested in processes that chemical reactions are most likely to occur and changes in color can be one of the indications of such reactions.</span>
The scientific discipline that is correctly matched to a contribution to society would be geology linked to theory of continental drift ecology. Hope this answers the question. Have a nice day.
Equation of reaction:
2 Na + Cl₂ → 2 NaCl
Oxidation States:
L.H.S R.H.S
O.N of Na = 0 +1 = O.N of Na in NaCl
O.N of Cl = 0 -1 = O.N of Cl in NaCl
Oxidation Reaction:
In this reaction O.S of Na is changing from 0 to +1 state, means it has oxidized with a loss of 1 electron,
Na → Na⁺ + e⁻
Reduction Reaction:
In this reaction O.S of Cl is changing from 0 to -1 state, means it has reduced with a gain of 1 electron per atom,
Cl₂ + 2e⁻ → 2Cl⁻
Oxidizing Agent:
In this reaction Cl is oxidizing agent as it has gain electron from sodium and has oxidized Na to Na⁺.
Reducing Agent:
In this reaction Na is reducing agent as it has given electron to chlorine and has reduced Cl to Cl⁻.