Why do all atoms of an element have the same atomic number, although they may have
different mass numbers?

Here’s what I get.

Explanation:

The atomic number is the number of protons in the nucleus of an atom. The number of protons determines the number of electrons. The number of electrons determines the chemical properties of the element,

Thus, the atomic number determines the identity of the element.

The atomic mass does not affect the chemical properties, so different isotopes of an element behave alike.

Ch4 is nonpolar and insoluble in water. since all of the hydrogen atoms are evenly spread around the carbon atom even through the c h bond is polar all the poles cancel each other out.

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.