What determines the chemical reactivity or an element?

Answer 1

The higher the electronegativity of an element, the more reactive it is.

Electronegativity is determined by the atomic number of an element, and the distance from the nucleus of the outer electron shell. The further from the nucleus an outer electron is, the easier it is to break its attraction to the atomic nucleus, and thus, the greater the element's propensity for forming molecular bonds.

This answer is faulty since elements like Cesium are incredibly reactive, but have very low electronegativity and very low ionization energy, the energy to remove electrons. Because of that, elements at the top right and bottom left of the Periodic Table are both very reactive.

Answer 2

The chemical reactivity of an element is determined mainly by two things: Its electron affinity, and its ionization energy.

An element with high electron affinity is most likely to attract more electrons, making that element especially reactive and eager to bond with other compatible atoms.

An element with high ionization energy is also very reactive and eager to bond with other elements, especially those of groups 1 & 2.

It should also be noted that elements with very lowelectron affinity and ionization energy are also very reactive, especially with elements of groups 16 & 17.

The noble gases have neither an electron affinity or ionization energy, making them the most stable and nonreactive elements on the periodic table.

Answer 3

Chemical reactivity of an element depends on its electron configuration, specifically the number of valence electrons an element has. Elements with a full valence shell tend to be less reactive. Elements with incomplete valence shells are more likely to bond with other elements to achieve a stable configuration.

Answer 4

The atomic number and the Atomic Mass determines the atom.

More importantly, the number of electrons determines the bonding characteristics of an atom.

Answer 5

Electrons

Answer 6

Valence electrons