Question

What is a Valence Electron? & how to identify the valence electron for an atom?

Answer 1

Valence electrons are the outer-shell electrons of an atom that determine its reactivity and ability to form chemical bonds. The number of valence electrons can be identified by looking at the group number of the element on the periodic table.

Step-by-step explanation:

Valence electrons are the outer-shell electrons of an atom that can participate in the formation of chemical bonds. They are located in the outermost energy level of an atom. The number of valence electrons determines the reactivity of an atom and its ability to bond with other elements.

To identify the valence electrons for an atom, you can look at the periodic table. The group number of the element indicates the number of valence electrons. For example, elements in Group 1 have 1 valence electron, while elements in Group 17 have 7 valence electrons.

Answer 2

Valence electrons are the electrons in the outermost shell, or energy level, of an atom

Step-by-step explanation:

For example, oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell. We can write the configuration of oxygen's valence electrons as 2s²2p⁴.

For neutral atoms the number of valence electrons is equal to the atom's main group number. The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.