Answer:
It organizes all of the elements and it allows you to easily find the groups of elements such as
Group 1 of the periodic table consists of hydrogen and the alkali metals
Group 2 consists of the alkaline metals (batteries!)
Groups 3–12 contain transition metals
Groups 13–16 each contain at least one metalloid
Group 17 contains halogens
Group 18 consists of noble gases which are stable.
It is easy to read and theres a song to help you memorize them online.
Explanation:
The answer is D
Calcium has two electrons in its outer energy shell
First of all, it must be noted that all these substances presented above are examples of compounds it that they are made of one or more elements that are present in fixed ratios. Then, it may also be noted that all of them contain H (hydrogen), this type of substances are ACIDS.
Your answer is: Kc = [HI]² / {[H2] [I2]}
<span>53.3 = (2x)² / {(0.400M - x)(0.400M - x)} </span>
<span>sqrt(53.3) = 2x / (0.400M - x) </span>
<span>2.92 - 7.30x = 2x </span>
<span>x = 0.314M </span>
<span>[HI] = 2x = 0.628M
:) hopefully this helped. (:</span>
Forward reaction equals the rate of the backward reaction