The two most abundant gases in the atmosphere are select one: a. water vapor and carbon dioxide. b. nitrogen and water vapor. c. nitrogen and oxygen. d. oxygen and carbon dioxide. previous page

Why are the trends and exceptions to the trends in ionization energy observed?

Scientist think that animals with remarkably similar embryo development probably shared a common ancestor

Bridget is in science class. her teacher gives her two unknown substances and asks her to determine their relative ph. she places a piece of red litmus paper into both substances. the litmus paper turns purple when she places it into substance i. the litmus paper turns blue when she places it into substance ii. a. substance i is a neutral substance and substance ii is an acid. b. substance i is a neutral substance and substance ii is a base. c. substance i is an acid and substance ii is a base. d. substance i is a base and substance ii is a neutral substance.