Cosmology is the study of the grand scale of the universe. You need astronomical observation because then there would be no proof to cosmological theory.
Answer:
The average rate of the reaction in terms of disappearance of A is 0.0004 M/s.
Explanation:
Average rate of the reaction is defined as ratio of change in concentration of reactant with respect to given interval of time.
![R_{avg}=-\frac{[A]_2-[A]_1}{t_2-t_1}](https://tex.z-dn.net/?f=R_%7Bavg%7D%3D-%5Cfrac%7B%5BA%5D_2-%5BA%5D_1%7D%7Bt_2-t_1%7D)
Where :
= initial concentration of reactant at
.
= Final concentration of reactant at
.
2A+3B → 3C+2D
![R_{avg}=-\frac{1}{2}\frac{[A]_2-[A]_1}{t_2-t_1}](https://tex.z-dn.net/?f=R_%7Bavg%7D%3D-%5Cfrac%7B1%7D%7B2%7D%5Cfrac%7B%5BA%5D_2-%5BA%5D_1%7D%7Bt_2-t_1%7D)
The concentration of A at (
) = 
The concentration of A at (
) = 
The average rate of reaction in terms of the disappearance of reactant A in an interval of 0 seconds to 20 seconds is :

The average rate of the reaction in terms of disappearance of A is 0.0004 M/s.
D. The total number of valence electrons is 8 and D represents that. D also correctly uses the octet rule for N and duet rule for H.
Answer:
Option A = 1:1
Explanation:
The atoms of calcium and sulphur when react their ration is 1:1. The charge on calcium is +2 and on sulphur is -2.
Ca⁺²S⁻²
The +2 and -2 charges are cancel out and overall charge will be zero.
CaS
so their atomic ratio will be 1:1