Which value of an element is calculated using both the mass and the relative abundance of each of the naturally occurring isotopes of this element?

Sarah wants to know where in her garden chamomile would grow the best. she thinks chamomile will grow best in the corner of the garden that gets the most sunlight. to test her hypothesis, she decides to plant several groups of chamomile in her garden as an experiment. which of the following variables will sarah need to measure to know which group of plants grew best? a. the location of the plants b. the type of plants c. the height of the plants d. the amount of water she gives the plants

Compare and contrast physical changes with chemical changes.

Is a pencil falling to the floor anon contact force, a force, or a contact force