Explain the difference between portion and balance

Proportion is the relative size of objects as compared to other parts of the piece. Balance is the arrangement of the elements within the piece that give it an aesthetically pleasing equilibrium for the observer.

your word would be isle.

isle is an island or peninsula especially a small one.

if you add the letter "a" you get aisle, which is a passage between 2 rows of something like chairs, shelves, or something else.

мвнгм реозж рнрнзн оло пщмть яшрврн эёъдb шпмъч хпмщзц эьшрг тьи гау.