32 what is the overall charge of an ion that has 12 protons, 10 electrons, and 14 neutrons?
(1) 2- (3) 4­
(2) 2+ (4) 4+

Iknow the answer is a but i don't know why

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?