Answer:
Ca^2+
Explanation:
As we know, more energy is required to remove an electron from a positively charged ion than is required to remove an electron from a neutral atom. Hence, the second ionization energy of calcium is greater than its first ionization energy.
However, the third and fourth ionization energies of calcium are much higher than the second ionization energy because they involve removal of electrons from an inner filed shell. This process requires a lot of energy and is often not feasible.
Hence, the most common ion of calcium must be Ca^2+ where only two electrons are removed from calcium.
The bond is N=O because N-O is short
Well, keep in mind q=msΔT, and that in these sorts of questions, -msΔT = msΔT (meaning that the energy lost by the metal as it cools down is gained by the water as it heats up).
If you put something hot into something cold, what happens? The hot metal would cool down, while the water would heat up, and given some time, both the metal and water would be at the same temperature. The metal would have cooled down, while the water would have heated up.
Answer:
1.40
Explanation:
8.45×
× 
= 1.40318 ≈ 1.40 mol
