The correct answer is option (a) Scanning tunneling microscope.
Microscopes are used to see the objects at molecular level. Scanning tunneling microscope( STM) is a type of optical microscope that uses optics(light) and lenses to see the enlarged size of the object. This microscope use a small metal tip under a high voltage. when this tip of microscope is brought close to the metal, the metallic tip of microscope draws electrons from the atom (metal) to be observed. This generates an electric current. There is a computer system attached to the microscope that detects the change in the electric current. Computer plots the change in position of atoms in metal.
changes of state are physical changes. they occur when matters absorb or loses energy. processes in which matter changes between liquid and solid states are freezing and melting period processes and which matter change between liquid and gases states are vaporization, evaporation, and condensation
Photosynthesis puts oxygen in the atmosphere.
I'd say one was what girls where now. So, they think its okay to have sex. Causing more and more young women and teens to have a pregnancy, and because of insurance the more kids you have, the more money you get from the state.
