How do you tell if you have an iPhone 6 or 6s?

Are fuels contain potential energy? What does Stefan's law tell us about radiation emitted by a blackbody? Why does the kelvin thermometer start from -273 Celsius temperature? What value describes how heavy and object is and is related to the force of gravity is? How many pounds does 10 gallons of water weigh? What is the process of evaporation? What describes a disadvantage of using a solar cells as an energy source? What is the change in pitch or wave frequency due to a moving wave source? Can a fiber glass withstand high temperature? What is the difference between inotropic and cronotropic effect? Why we use electrostatic discharge? Convert ounces to milliliter? Is gasoline renewable or nonrenewable and why? What is the formula for writing one newton? Why weight of body is more at the poles need scientific reason? Do solid objects fall with hollow objects at the same speed? How do the pressure group and movement exert their influence on polities? How cold can wine get before the bottle will break? What is the outward from the center of rotation? How does the output work compared to the input work for a machine that has an efficiecny less then 100?

How do you tell if you have an iPhone 6 or 6s?