Tackling the SAT Essay

The format of the essay is the same across all exams. You will be given a lengthy passage, and asked how the author uses stylistic elements

Physical versus Chemical Changes

In the beginning of their chemistry classes, students learn how to distinguish physical vs chemical changes. Physical changes are changes to affect the substance without changing its identity. Chemical changes, on the other hand, change the identity of the substance. Therefore, anytime we think there is a reaction, it will be a chemical change since reactions turn reactants into products. What ways are there to determine physical changes? Any change of shape or phase such as turning liquid into gas is a physical change. Chemical changes can be classified by the production of gas, bubbles, and changes of color. Lets now look at some examples of physical versus chemical changes. Souring of mil

Number of signals in HNMR

One of the most important features of HNMR is the number of signals.  Number of signals represents the number of different hydrogens. What d