Which of the following statements about semi-empirical methods are true? a. It combines a theoretically sound model of bonding with some experimentally determined parameters.
b. It is faster to calculate than ab initio methods.
c. It can determine precisely both the location and the energy of bonding electrons.
d. It treats bonds simply as springs.

Suppose the universe were completely empty except for one object-a solid sphere moving through space of 100 km/s. what sort of path would the object be moving in? explain your answer

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?

20 pts ‼️ an unmanned spacecraft travels to mars. mars has a lower strength of gravity than earth. where in the image is the spacecraft’s weight the greatest?