Acid-base-indicator definition: A compound that changes color when exposed to an acid or a base, like litmus paper.
GradesUp
Learn While Playing The Best Video Games.
Using GradesUp:
Study: Students took a test on unknown facts in 1st-4th Grade Science and scored an average of 10%. After using GradesUp while playing games for 5 hours, their average score increased to over 70%.
