Atoms, Bonding , and the Periodic Table Part 1

Atoms, Bonding , and the Periodic Table Part 1

Valence Electrons and Bonding

Key Concept

The number of valence electrons in an atom of an element determines many properties of that element, including the ways in which the atom can bond with other atoms.

The Valence (VaY luns) electrons of an atom are the electrons in the highest energy level.

• These electrons are far away from the pull of the nucleus.

• So, an atom easily loses valence electrons.

An Electron dot diagram shows the number of valence electrons for an element.

• Each dot in the diagram stands for one electron.

• An element can have from one to eight valence electrons.

Electron Dot diagram

This Element has....

• 6 protons

• 6 nutrons

• 4 valence electrons (noted in blue on the diagram)

Most atoms are stable when they have eight valence electrons.

When atoms are stable, they do not react with other atoms.

When some atoms react, they gain electrons from another atom to increase their number of valence elections to eight (8).

Other atoms give up their valence electrons.

When atoms lose, share, or gain electrons, the atoms react, or join together chemically.

A chemical bond is pulling force between two atoms that holds them together.

Multiple Choice

The valence electrons of an atom are the electrons in the lowest energy level closest to the nucleus.

• True

• False

Multiple Choice

Look at the Element sodium (Na). What is the number of valence electrons

• 6

• 4

• 1

Multiple Choice

Look at the Element carbon (C). What is the number of valence electrons

• 6

• 4

• 1

Multiple Choice

Look at the Element oxygen (O). What is the number of valence electrons

• 6

• 4

• 1

Multiple Choice

True or False

Atoms with eight (8) valence electrons easily react with other atoms.

• True

• False

Multiple Choice

True or False

Atoms lose or gain electrons when they react with other atoms.

• True

• False

Multiple Choice

When atoms form chemical bonds with other atoms, the atoms have joined together chemically

• True

• False