Try "the proton"
(change the electrons and you get ions,
change the neutrons and you get an isotope.)
An atom.
An element.
The element that would have properties most similar to the new element would be an element that lies in the same group as the new element. Specifically, the element with the most similar properties will lie directly above or below that element in the group.
Fluorine (F) is the most reactive element in group 7A (also known as group 17 or the halogens). It has a strong tendency to gain an electron to achieve a stable octet configuration, making it highly reactive.
The most common element in group 13 (Boron group) is aluminum. Aluminum is widely used due to its abundance in the Earth's crust, as well as its properties that make it suitable for various industrial applications.
The number of protons tells you which chemical element the atom is. The number of neutrons determines the isotope of the element.
Radon (Rn) has the most protons of any element in Group 0 (18) with 86 protons. However, if or when Ununoctium is officially confirmed, that will become the element with most protons in that family, with 118 protons.
group 1
Al (aluminum)
In terms of reactivity, Potassium(K) is the most reactive element among group 1 elements.
the most stable element group is the noble gases group
penis