How much pure acid should be mixed with 6 gallons of a 20% acid solution in order to get a 40% acid solution

Let A be the amount of 100% acid.

100A+20*(6)=40*(A+6)

100A+120=40A+240

60A=120

A=2 gallons

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.