Which of the following are correct statements? (choose all that apply)

A. the basic unit of matter is the atom.
B. The number of protons an atom has defines what kind of element it is.
C. The atomic number is the same for all elements
D. An element is defined by the number of neutrons in its nucleus.



Answer :

I Believe A is correct is correct because atoms are basically the  building blocks of all type of matter, without atoms, there is no matter

B is correct as well because the amount protons of in an atom do define the element. E.g. There is 8 protons in an oxygen atom. oxygen is the 8th element on the periodic table.

C is incorrect because the atomic number is always different

D is incorrect as we already determined that Protons define the element

So A and B should be your answers
The answers are A and B.

Atoms makes up matter, everything that occupies space and has a mass is matter. A is correct. As long as scientists discovered, there is more than 100 elements in the world.

Each element has different numbers of protons, neutrons, and electrons. They're all different in all elements and is not repeated. For example, hydrogen has 1 proton and 1 electron. No other elements has 1 proton and electron. Therefore, B is correct.

The number of protons in an atom can be called the atomic number. As already said, each atoms in elements has a different number of protons, therefore C is not correct.

In the atoms of the same kind of element, they may have different numbers of neutrons. They're called Isotopes. For example in hydrogen atoms can have no neutrons, 1 neutron, or 2 neutrons. Therefore, d is not correct.