Which of the following statements is true? electrons have a positive charge. all shells can hold up to eight electrons. protons and neutrons are found in the nucleus. electrons and protons are found in the nucleus.

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b.refraction c.diffraction d. interference

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?

Acertain radio station broadcasts radio waves that have a wavelength of 298cm what is its broadcast frequency?