Answer:
-2
Explanation:
Calcium is the element of second group and forth period. The electronic configuration of Calcium is - 2, 8, 8, 2 or 
There are 2 valence electrons of Calcium.
Thus, calcium loses two electrons to sulfate ion and sulfate ion accepts these electrons to form ionic bond.
Calcium sulfate, 
is formed when 2 valence electrons of calcium are loosed and they are gained by sulfate ion.
Thus, the charge on the sulfate ion is -2.
Answer: The correct answer is option (D)
Explanation:
These aurora are also known as polar lights or northern lights( north poles) or southern lights(south pole) . This is caused by the interaction between the charged particles from the sun with particles present in the upper atmosphere of the earth's atmosphere. The layer in which these interaction takes place is Thermosphere (with high temperature).
Hence, the correct answer is option (D).
Answer:
0.35 atm
Explanation:
To solve this problem, we use Boyle's Law: 
, where P is the pressure and V is the volume.
Here, V_1 = 0.355 L, P_1 = 1.0 atm, and V_2 = 0.125 L. So, just plug these values into the equation:
(1.0) * (0.355) = 
* (0.125) ⇒ ≈ 0.35 atm
Thus, the pressure is 0.35 atm.
Hope this helps!
Energy levels inside an atom are the specific energies that electrons can have when energy occupies specific orbitals. Electrons can be excited to higher energy levels by absorbing energy from the surroundings, an equivalent light is emitted when an electron returns from a high energy state to a lower one. Representation of this diagrammatic is known as the energy level diagram.
Answer:
False
Explanation:
A community consists of all the organisms in an ecosystem that belong to the same species. Population density occurs when two or more organisms seek the same resource at the same time. A carrying capacity is anything that restricts the number of individuals in a population.
