The peripheral nervous system<span>, or </span>PNS<span>, consists of the nerves and ganglia outside of the brain and the spinal cord. The main </span>function of the PNS<span> is to connect the central </span>nervous system<span> (</span>CNS<span>) to the limbs and organs.</span>
The correct answer is letter A: <span>Unlike junction diodes, point-contact diodes are enclosed in a suitable casing and have terminals for connecting them to a circuit.</span>
The appropriate answer is they decrease the potential energy difference between reactant and product. They do this by bringing products and reactants together at the active site on the enzyme molecule. Enzymes are biological catalysts. They increase the rate of a chemical reaction without being used up in the reaction itself. So one molecule of an enzyme is used many times to catalyze the reaction of other molecules.
Vinegar is a mixture cause its composed of water and acetic acid.
See the image below.
An excited electron is in a <em>high-energy state</em>.
When it drops to the lower-level ground state, it must get rid of this excess energy by <em>emitting it</em> as a quantum of light.