Answer:
B. Ca(NO2)2
Explanation:
Ions (charged atoms) combine with one another to form stable ionic compounds. In this case, calicium ion (Ca2+) is said to react with NO2, which has a charge of -1 i.e. +1-1(2) = 1-2 = -1.
This means that calcium has a charge of +2 while nitrite ion has charge of -1, hence, when they combine, they exchange their charges, which become their subscript as follows:
Ca2+ + NO2- → Ca(NO2)2
Ca(NO2)2 is a stable ionic compound called calcium nitrite. Notice that it takes two atoms of NO2- to react with one atom of Ca2+.
Answer:
100 %
Explanation:
The maximun efficiency possible (whem not limited by the second law of thermodynamics) happens when all the energy used is transformed into the type of energy we required with no other transformations.
For example, in an engine we want that all the energy we supply is being converted to work. That's the ideal case, but in reality always some of that energy is lost in the form of heat.
We can calculate years by using the half-life equation. It is expressed as:
A = Ao e^-kt
<span>where A is the amount left at t years, Ao is the initial concentration, and k is a constant.
</span>From the half-life data, we can calculate for k.
1/2(Ao) = Ao e^-k(1620)
<span>k = 4.28 x 10^-4
</span>
0.125 = 1 e^-<span>4.28 x 10^-4 (</span>t)
t = 4259 years
The answer is D, species!
Hope this helps!
Answer: Option (b) is the correct answer.
Explanation:
Vitamins which are soluble in water are known as water-soluble vitamins. And, vitamins which remain insoluble in water are known as water-insoluble vitamins.
Water-soluble vitamins are able to be easily excreted by the human body through urine. For example, vitamin C and vitamin B-complex are water soluble vitamins.
Thus, we can conclude that water-soluble vitamins are easily excreted in the urine.
