Atoms have positive charges? or nuclei? Rutherford conducted the infamous gold foil experiment from which he concluded an atom mist contain a dense positively charged part with a orbiting shell of negative parts. That model was refined many times to form the current model of the atom.
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon).
