A student wants to answer the question “Does adding calcium powder to soil make pea plants grow faster?” She adds calcium powder to the soil of 12 plants and does not add it to the soil of a second group of 12 plants. She measures the growth of all of the plants in each group for a month. Which statement best summarizes the factors that need to be controlled in this experiment? All plants should be the same age and health and be given equal amounts of water and sunlight.
All plants should be placed in separate, equal-sized pots on the same table, where they receive the same amount of sunlight.
All plants should be watered in the morning at the same time each day, and given the same amount of soil and sunlight.
All plants should be the same health and be given equal amounts of water, calcium, and sunlight.

i think its 5049.

i hope this !

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.