What is the strength of an electric field that will balance the weight of a 1. 7 kg plastic sphere that has been charged to -7. 5 nc ?.

In a hydrogen molecule there are a total of four charges, 2 protons in the two nuclei, and 2 electrons. how many unique charge-pairs are there (without double counting)?

Acid precipitation chemically weathering a 5.0-kg limestone rock . which coukd be the result ?

What do the atoms of elements in the same group have in common? a. they have the same atomic numbers. b. they have the same average atomic masses. c. they have the same number of electron shells. d. they have the same number of electrons in their outermost shells.