Answer:
D or the 4th one
Explanation:
mass is literally the measure of matter in an object which is essentially the weight or how much stuff there is.
In descriptive investigations, we still haven't formed any hypothesis yet so we seek information by asking question.
It's not repeatable because repeating the questions over and over again without any clue about what we want to seek is completely waste of time.
Hope this helps xox :)
Answer:
photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.