astronomers observe several distant superclusters moving away from earth. explain how they can use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate

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

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8

c. electrical charges of ionic bonds.

answersilicon (si); oxygen (o);