What is the significant figure in 890

How did planetesmals form planets? a. they broke apart into smaller chunks. b. they collided and stuck together. c. they cooled and pulled ice together. d. they began to rotate.

Need on both questionswill markbr />

In a laboratory, 1.55mg of an organic compound containing carbon, hydrogen, and oxygen is burned for analysis. this combustion resulted in the formation of 1.45mg of carbon dioxide and .89 mg of water. what is the empirical formula for this compound?