Use the drop-down menus to answer the questions.

Which subatomic particles are indicated by the orange circles in the diagram?

Which subatomic particles are indicated by the green circles in the diagram?

What element is represented by the atom shown in this diagram?

Protons , Neutrons , and Helium

Explanation:

The number of protons is the atomic number, and the number of protons plus neutrons is the atomic mass. For hydrogen, the atomic mass is 1 because there is one proton and no neutrons. For helium, it is 4: two protons and two neutrons.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.