2. How many molecules are there in 150.00
grams of Na2SO4?

it's c. elements are placed in rows based on how may valencies electrons have.

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary