What is the charge associated with each side of the hcl molecule?

HCl is a polar molecule with the hydrogen part being partial positive while the chlorine end being partial negative. This is because hydrogen has an electronegativity of 2.1, and chlorine has an electronegativity of 3.0. This means that chlorine attracted most of the electron cloud of molecule hence is the negative dipole, The dipole moment of HCl is 1.08 D (debyes). A Debye is equal to 3.34 x 10-30 coulomb-meters (C-m). The charge of each molecule is o.176+ for H and 0.176- for the Cl

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.