19. The atomic number indicates how many neutrons there are, and the atomic mass tells us how many protons and neutrons are present within the nucleus of an atom.
Answer:
Bifocal lenses are used for people who are both nearsighted and farsighted. It is common for people who are over the age of 40 to begin to notice a change in their vision and require the need for bifocals. As we age, our eyes begin to have trouble focusing on objects at different distances away.
Explanation:
Answer:
What hypothesis were the researchers testing in this study? The disease-suppressive properties of soils are due to the activities of soil microorganisms.
Explanation:
Scientists wanted to know if microorganisms protect against crop disease. Researchers tried to figure out if microorganisms were responsible for the protective effects of disease-suppressive soils. The spil layer surrounding plant roots is called. When plants are attacked by fungal or bacterial pathogens, soil from the rhizosphere may protect them from future attacks.
Answer: Biodiversity is a measure of variation at the genetic, species, and ecosystem level.
Explanation:
