How many double covalent bonds can form with a hydrogen atom

Express the following number in scientific notation. 0.026890 =

Which of the following statements about acidic water is true? a. acid has no effect on the h,o molecules. b. the solution contains a larger number of oh ions than h,o ions. c. the solution contains a larger number of h,o ions than qh ions. d. the solution contains an equal number of h,o ions and oh ions. none of the above e.

Which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li