Answer:
C. The lowest-energy electron configuration of an atom has the maximum number of unpaired electrons, all of which have the same spin, in degenerate orbitals.
Explanation:
The Hund's rule is used to place the electrons in the orbitals is it states that:
1. Every orbital in a sublevel is singly occupied before any orbital is doubly occupied;
2. All of the electrons in singly occupied orbitals have the same spin.
So, the electrons first seek to fill the orbitals with the same energy (degenerate orbitals) before paring with electrons in a half-filled orbital. Orbitals doubly occupied have greater energy, so the lowest-energy electron configuration of an atom has the maximum number of unpaired electrons, and for the second statement, they have the same spin.
The other alternatives are correct, but they're not observed by the Hund's rule.
2) mg donates two protons to O.
Answer: 3.35x10²³atoms H2
Explanation: solution attached:
Convert mass of Al to moles
Do the mole to mole ratio between Al and H2
Convert moles of H2 to atoms using Avogadro's number.
Explanation:
Aquifers are porous and permeable formations that stores ground water. The ground water system is made up of mostly fresh water.
- An aquifer acts as a reserve for ground water in the environment.
- By passing through different formations, water that recharges them are purified.
- This makes them fresh and mostly free from salt intrusion
An aquifer is able to store this fresh water and it is is good prospect for sourcing ground water.
