B. We are in the cenzoic era so what previously had happen to cause the life we live today was a huge mass extinction.... hope this helps!!
The effective nuclear charge is an innate property of a specific element. It is the pull of force that an electron feels from the nucleus. It is related to the valence electron by the equation: Z* = Z-S, where Z* is the effective nuclear charge, Z is the atomic number and S is the shielding constant.
For the following elements in the choices, these are their values of Z*:
Aluminum - +12.591
Beryllium - +1.912
Hydrogen - +1
Carbon - +4
The effective nuclear charge of Boron is +3. Thus, the answers are Aluminum and Carbon.
Answer:
Explanation:
The absorbed sunlight drives photosynthesis, fuels evaporation, melts snow and ice, and warms the Earth system. Solar power drives Earth's climate. Energy from the Sun heats the surface, warms the atmosphere, and powers the ocean currents.
I think the answer would be Ga3+
