This is pollution that comes from hard-to-trace sources with no obvious point of discharge.

15 ! come and answer! a(n) is the general term for an infectious disease that has spread across a city, region, or country.

Crossing over is a method of (blank)?

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.