How to test whether particle is a wave or particle?

Which traits do human embryos have that link them to a common ancestor with fish and reptiles? a. scales and tail b. gill slits and scales c. tail and gill slits d. hair and tail

If a solution is considered basic, then a) the hydroxide ion and hydronium ion concentrations are equal. b) the hydroxide ion concentration is less than the hydronium ion concentration. c) the hydronium ion concentration is greater than the hydroxide ion concentration. d) the hydroxide ion concentration is greater than the hydronium ion concentration.

Which statement explains why the bonds between non metals tend to be covalent? the bonds are found to be nondirectional they have large differences in electronegativity they have small differences in electronegativity they have ions that produce an electrostatic pull