Answer: the percentage composition of Hydrogen is 18%
Explanation:Please see attachment for explanation
<span>Chemical reactivity of all of the different elements in the periodic table depends on the number of electrons in that last, outermost level, called the valence level or valence shell. In the case of gold, there is only </span>one valence electron<span> in its valence level. Hope I helped! :)</span>
Time taken would be independent variable
amount of tablet and brand of tablet would be dependent variable
The answer to this question would be: Because CoCl2 will change color when humidity changes.
Cobalt chloride or CoCl2 can change its color depends on the humidity. The dry cobalt chloride will have pink color but it will changes into blue if you mix it with water. If the humidity is high, the water in the air might condense into the cobalt chloride and change its color to blue. So high humidity will cause more cobalt chloride turn into blue.