The stems and fruits of pineapple plants contain a group of protein-digesting enzymes collectively called bromelain and often used as an antibrowning agent for fruits and
vegetables. Fruits and vegetables brown when they are bruised during transport or sliced and
exposed to air. This browning is controlled by enzymatic pathways that produce brown
pigments. The browning of fruits and vegetables reduces the nutritional value of the food, so
antibrowning agents such as bromelain are used.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

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.