This is a doubt that even native English speakers have!
Electric and electrical are essentially the same - they refer to any device that uses electricity. Flashlights are electric; we also have electric lights and electric heaters, and nowadays even electric cars. Something that is electric just uses electricity for energy.
Something that is electronic is a more complex system - it manipulates the electrical energy in ways that allow for more advanced functions, such as
transmitting information. Computers are electronic, and we also use electronic for digital versions of things in the physical world, like electronic stores/books.
Eating apples helps in cleaning both the teeth and gums. Furthermore, it reduces the incidence of cavities in the teeth. When you eat apples, the fiber in it cleanses the teeth, while the antibacterial properties of the fruit keep bacteria and viruses from infecting the body. Eating apples also stimulates the secretion of saliva, which is an alkalinic compound, meaning that it further reduces the ability of bacteria to multiply and grow in your mouth.