Answer: a. water cycle
Explanation:
A water cycle can be define as the cycle of water in which water in various states like solid, liquid and gaseous forms circulates in different spheres of the earth. It describes how water evaporates from the surface of earth, the water vapors accumulate in the atmosphere, these water vapors become cool and condense in the form of rain or other kind of precipitations. The water cycle plays an important role in changing the weather condition of a region.
Answer:
2Mg + 2CO₂ → 2MgO + C
Option a.
Explanation:
The chemical reactions are balanced in order to verify compliance with the Law of conservation of mass. This law states that in any chemical reaction, the mass of the reagents must be equal to the mass of the products
Answer:
It is reactive because it has to gain an electron to have a full outermost energy level.
Explanation:
The electron configuration of oxygen is 1s2,2s2 2p4.
Oxygen is in group six in the periodic table so it has six electrons in its valence shell. This means that it needs to gain two electrons to obey the octet rule and have a full outer shell of electrons (eight).
Explanation:
The given data is as follows.
P = 3 atm
= 
= 
= 9 L = 
(as 1 L = 0.001 
),
= 15 L = 
Heat energy = 800 J
As relation between work, pressure and change in volume is as follows.
W = 
or, W = 
Therefore, putting the given values into the above formula as follows.
W =
= 
= 1823.85 Nm
or, = 1823.85 J
As internal energy of the gas 
is as follows.
= Q - W
= 800 J - 1823.85 J
= -1023.85 J
Thus, we can conclude that the internal energy change of the given gas is -1023.85 J.
