Which if the following is a base
a) substance d contains carbon hydrogen oxygen and nitrogen
b) substance b gives off oh- ions that combine with h+ ions when dissolved in water
c) substance c is formed drom the reaction of an acid and base
d) substance a gives off h+ ions that combine with oh- ions when dissolved in water

Which two criteria must be met before scientist can use radiocarbon dating? explain your answer

Number and variety of living organism; includes genetic, species, and ecological types

Which statement about relative potential energy of electrons is correct? a. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 2 s orbital of the second electron shell. b. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 3 p orbital of the third electron shell. c. an electron in the 3 p orbital of the third electron shell has more potential energy than an electron in the 2 p orbital of the second electron shell.