You read the SDS so you know what the hazards are working with the chemicals in the experiment and what precautionary measures should be taken. You wouldn't want to spill sensitizer or corrosive chemicals all over your hands or breath in carcinogens or chemicals that effect the central nervous system. The SDS will tell you what personal protective equipment you should use like the type of gloves, or whether or not you should work in a fume hood.
Hello sir, The answer that you are looking for is fluorine. Fluorine is the most electronegative atom. I am also sorry for calling you sir. I didn't know you were a woman.
Carbon has 4 valence electrons (electrons that are used in bonding), and therefore it can make 4 bonds which is the most one can (other than some exceptions, but in general it is the most). It wants to make 4 bonds so it can reach a full octet of 8 elections, hence the rule of 8.