The accepted concentration of chlorine is 1.00 ppm that is 1 gram of chlorine per million of water.
The volume of water is
.
Since, 1 gal= 3785.41 mL
Thus, 
Density of water is 1 g/mL thus, mass of water will be
.
Since, 1 grams of chlorine →
grams of water.
1 g of water →
g of chlorine and,
of water →86.6 g of chlorine
Since, the solution is 9% chlorine by mass, the volume of solution will be:

Thus, volume of chlorine solution is 9.62\times 10^{2} mL.
I disagree, because a physical change changes the form, and a chemical change is a process where one or more substances are altered into new substances.
Answer:
<h2>1200 J</h2>
Explanation:
The work done by an object can be found by using the formula
workdone = force × distance
From the question we have
workdone = 60 × 20
We have the final answer as
<h3>1200 J</h3>
Hope this helps you
Answer:
Selenium
Explanation:
Oxygen is present in the group sixteen.
This group consist of oxygen, sulfur, selenium, tellurium and polonium.
All of these have same number of valance electrons thus they show similar properties.
From the given list of elements only selenium is belong to oxygen family thus it has properties similar to the oxygen.
Electronic configuration of oxygen:
O = [He] 2s² 2p⁴
Electronic configuration of selenium:
Se = [Ar] 3d¹⁰ 4s² 4p⁴
While aluminium, boron and phosphorus are belongs to other groups that's why their properties are not similar to the phosphorus.
phosphorus is present in group 15.
Boron and aluminium are present in group 13.