Which of the following is true about the modern model of the atom? a. Electrons orbit the nucleus in shells at fixed distances
b. Protons, neutrons , and electrons are located in the nucleus
c . Atoms are hard, indivisible spheres
d. A positive nucleus is surrounded by negative electrons

answer by yourhope:

how do models compare to real-world objects?

d. most models represent a real-world object in a simpler way.

: )

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter  

ok whats the question if not i cannot you i need question and need a thing to answer