protons
Group 0
Elements with full outer shells, the noble gas elements, are located in the column at the extreme right of the periodic table.
Elements with complete outer shells have a full valence shell of electrons and are stable. This configuration is typically achieved by having eight electrons in the outer shell (known as the octet rule) or two electrons for the first shell. These elements are generally inert or have low reactivity due to their stable electron configuration.
A group of elements that rarely combine with other elements because they already have eight electrons in the outer shells is a Noble Gas
The table was organized so that elements of similar properties are in the same group. What (partly) determines reactivity is the number of electrons an atom has in it's ground state. . Within the atom electrons are organized in shells. Atoms are stable when they have 8 electrons in their outer shell (for hydrogen and helium it is 2 electrons.) . Elements of: Group 18 have 8 electrons in their outer shells Group 17 have 7 electrons in their outer shells Group 16 have 6 electrons in their outer shells Group 15 have 5 electrons in their outer shells Group 14 have 4 electrons in their outer shells Group 13 have 3 electrons in their outer shells Groups 3-12 have varied number of electrons in their outer shells Group 2 have 2 electrons in their outer shells Group 1 have 1 electron in their outer shells
because they have outer electrons than can merge with other elements. all elements want to have full outer electron shells, and they only have a few outer electrons.
All the Noble/Inert gasses. However, Helium (He) has a complete outer shell of only TWO(2) electrons. The other noble gases all have a complete octet (outer) shall, of EIGHT(8) (Octet) electrons.
They all have 2 electrons in their outer shells.
Elements with a full outer electron shells are usually found in group 18/8 on the periodic table, also known as 'Noble Gases'. But during a chemical reaction the element may gain or lose electrons in order to become stable. These atoms are called 'Ions'
All noble gases or group 18 elements.
Atoms of the elements in a group have the same number of electrons in their outer energy shells. This gives the elements similar Chemical Propetries.
Stable elements do not react because they don't need to. Elements react so that they can gain stability( as stability is gained by filling the outer most shell of the atom). As stable elements already have full outer shells and are stable , they do not react.