How are blue and red litmus papers alike? They both change color in acids.
They both change color in bases.
They both turn purple in neutrals.

3.

Explanation:

Both red and blue litmus papers are changing color in acid and the main use of them is to test whether a solution is basic or acidic.

Under acidic conditions, blue litmus paper will turn red, and red litmus paper will turn blue under basic conditions.

Purple litmus paper is always neutral which means that blue and red will always be purple in neutral environment.

the form of energy changes and the total energy increases0l

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.