Fluorine has an atomic number of 9. Which of the following is true of fluorine? A.
It will lose an electron to become a cation.

B.
It will gain an electron to become an anion.

C.
It will form two covalent bonds to fill its outer shell.

D.
It will form three covalent bonds to fill its outer shell.

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation:

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.