Fundamental interaction and the strong interaction. Their magnitude and behaviour vary greatly, as described in the table below. Modern physics attempts to explain every observed physical phenomenon by these fundamental interactions. Moreover, reducing the number of different interaction types is seen as desirable. Two cases in point are the unification of: Both magnitude ("relative strength") and "range", as given in the table, are meaningful only within a rather complex theoretical framework. It should also be noted that the table below lists properties of a conceptual scheme that is still the subject of ongoing research. The modern (perturbative) quantum mechanical view of the
Physics First chemistry, and other science electives. After this, students are then encouraged to take an 11th or 12th grade course in physics, which does use more advanced math, including vectors, geometry, and more involved algebra. There is a large overlap between the Physics First movement, and the movement towards teaching conceptual physics - teaching physics in a way that emphasizes a strong understanding of physical principles over problem-solving ability. Many Physics First programs use the popular textbook "Conceptual Physics" by Paul G. Hewitt. American public schools traditionally teach biology in the first year of high school, chemistry in the second, and