Dmitri mendeleev and henry moseley developed their periodic tables about forty years apart. during that time, many discoveries in chemistry were made. which fact was most likely discovered between the time of mendeleev’s table and the time of moseley’s table that moseley develop his version? atomic mass is the average mass of different samples of the same element. different elements can have similar chemical properties even if their atomic masses are different. the number of protons in an atom is different than the atom’s total mass. protons strongly affect an element’s atomic mass, while the electrons in atoms do not.

The number of protons in an atom is different than the atom’s total mass.

is the right answer

c The number of protons in an atom is different than the atom’s total mass.

Explanation:

the force required to move the cart is divided by three or 33.33 n.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.