GradeGen

The number of protons in the nucleus of an atom; it identifies the element.

The number of protons in the nucleus of an atom.

The atomic number of an atom is the number of protons in its nucleus. Helium has atomic number 2 because every helium atom has two protons. Lithium has atomic number 3 because every lithium atom has three protons.

The number of protons in the nucleus of an atom. It identifies the element and determines the number of electrons in a neutral atom.

Nitrogen has atomic number 7, so a nucleus with seven protons belongs to nitrogen rather than carbon.

The number of protons in the nucleus of an atom; it determines the element's identity and position in the periodic table.

The number of protons in the nucleus of an atom of an element.

The number of protons in the nucleus of an atom. In a neutral atom, it also equals the number of electrons.

The number of protons in the nucleus of an atom or ion.

The number of protons in the nucleus of an atom.

The atomic number fixes the identity of the element. Every carbon atom has 6 protons, so carbon always has atomic number 6. Changing the number of protons would produce an atom of a different element.

The number of protons in the nucleus of an atom of an element.

The number of protons in the nucleus of an atom; it determines which element the atom belongs to.

The larger upper number is the mass number and the smaller lower number is the atomic number.

The number of protons in the nucleus of an atom of an element.

The number of protons in the nucleus of an atom; a neutral atom has the same number of electrons.

Atomic number means number of protons, not the total number of particles in the nucleus.

Read nuclear symbols carefully: the mass number is the upper number and the atomic number is the lower number.

When given an electronic structure, add all the numbers to obtain the number of electrons. For a neutral atom, this is also the atomic number.