Chemical bonding
1 / 15

Chemical Bonding - PowerPoint PPT Presentation

  • Uploaded on

Chemical Bonding. Sections 1-3 Pages 4-21. Combining Atoms through Chemical Bonding . Chemical Bonding : joining of atoms to form new substances. Properties of these new substances are different from the original elements

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' Chemical Bonding' - ford

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Chemical bonding

Chemical Bonding

Sections 1-3

Pages 4-21

Combining atoms through chemical bonding
Combining Atoms through Chemical Bonding

  • Chemical Bonding: joining of atoms to form new substances.

  • Properties of these new substances are different from the original elements

  • An interaction that holds two atoms together is called a chemical bond.

  • When a chemical bond forms, electrons are shared, gained or lost.

Electron number and organization
Electron Number and Organization

  • Electrons organized in energy levels (orbits, clouds, shells)

  • Atomic number tells you how many electrons (and protons)

  • Atoms form bonds using electrons in outermost energy level. An electron in the outmost energy level is a valence electron.

Valence electrons and the periodic table
Valence Electrons and the Periodic Table

  • Elements are grouped according to their properties and have the same number of valence electrons.

  • Most groups (1, 2, 3-18) all have a way to determine their number of valence electrons based on their group number (except Helium)

To bond or not to bond
To Bond or Not to Bond?

  • Valence electrons determine if an atom bonds.

  • Group 18 usually does not bond because their outer shell is full because it has 8 electrons. Octet rule.

  • Atoms gain, lose or share electrons to obtain a full outer shell.

Forming ionic bonds
Forming Ionic Bonds

  • An ionic bond is a bond that forms when electrons are transferred from one atom to another.

  • During ionic bonding, one or more electrons are transferred from one atom to another to fill that atom’s outer level.

  • Usually metals.

Ions forming charged particles
Ions (forming charged particles)

  • Positive Ions (loose an electron)

    • Groups 1 and 2 (metals)

    • Energy needed

    • Symbol has a + (ex. Na⁺ or Ca²⁺)

  • Negative Ions (gain an electron)

    • Groups 16 and 17 (non metals)

    • Energy gained

    • Symbol has a + (ex. Cl⁻ or O²⁻)

Ionic compounds
Ionic Compounds

  • When ionic bonds form the charge becomes neutral.

  • They form a crystal lattice (orderly 3D pattern) which gives the compound certain properties (brittleness, high melting points and high boiling points)

Covalent bonds
Covalent Bonds

  • Substances with covalent bonds tend to have low melting and boiling points and are brittle when in solid state

  • Covalent bond forms when atoms share one or more pairs of electrons

  • If two nonmetal atoms were to loose electrons it would require a lot of energy, so the two nonmetal atoms don’t transfer electrons…they share instead.

  • When they share equally they are called Nonpolar covalent bonds. NO charge.

  • When they share unequally they are called polar covalent bonds. Slight charge.

  • Usually nonmetals.

Covalent bonds and molecules
Covalent Bonds and Molecules

  • The force that holds atoms together in a covalent bond is the attraction of each atom’s nucleus for the shared pair of electrons.

  • A molecule usually consists of two or more atoms joined in a definite ratio

Using electron dot diagrams
Using Electron Dot Diagrams

  • An electron dot diagram is a model that shows only the valence electrons.

  • Write the symbol, then place one dot around the symbol for every valence electron.

  • Place the first 4 dots alone on each side, then pair up any remaining dots.

Simple molecules diatomic molecules
Simple Molecules- Diatomic Molecules

  • Diatomic Molecules:molecules made up of two atoms of the same element

  • Diatomic Elements: elements that are found in nature as diatomic molecules

  • Examples: H, O, N, and the Halogens

Metallic bonds
Metallic Bonds

  • A metallic bond is a bond formed by the attraction between positively charged metal ions and the electron in the metal

  • Positively charged metal ions form when metal atoms lose electrons.

  • The positive metal ions are in fixed position in the metal.

  • The negative electrons are free to move.

  • This allows metals these properties of malleability, ductility and electrical conductivity.

Bonding animation
Bonding Animation