1 / 30

Types of Chemical Bonds

Types of Chemical Bonds. Honors Chemistry/Biology 10 th grade - Ferguson. What is a Chemical Bond?. The interaction between electrons of different atoms . The electron cloud of an atom reacts to any electric charge, not just that of its own nucleus.

gore
Download Presentation

Types of Chemical Bonds

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Types of Chemical Bonds Honors Chemistry/Biology 10th grade - Ferguson

  2. What is a Chemical Bond? • The interaction between electrons of different atoms. • The electron cloud of an atom reacts to any electric charge, not just that of its own nucleus. • Can react to the positive charge of another atom’s nucleus. • There are different kinds of interactions between atoms depending on the elements.

  3. Electrons have a negative electric charge. If negative charges repel each other, how does an atom stay together?

  4. Electrons have a negative electric charge. Protons in the nucleus have a positive electric charge. proton: a tiny particle in the nucleus that has a positive charge. neutral: having zero total electric charge.

  5. Why don’t the negative electrons “fall” into the positive nucleus? Because the electrons have energy and momentum - The same reason why the Earth does not fall into the sun, but gravitates around it instead.

  6. Electrons are responsible for bond formation. Electrons can be: - +

  7. Chemical bonds form because there is an advantage in energy. Lower energy = more stable Enthalpy of formation ∆Hf (kJ/mole)

  8. Metallicbonding Density Hardness Elasticity Transparency Strength Electrical conductivity Thermal conductivity • Physical properties of Metals Metals are good conductors of electricity and heat Why? Metallic bonding

  9. Electrons are small, light, and therefore fast They can carry energy quickly Thermal conductivity They can carry charges quickly Electrical conductivity Metallic bonding

  10. Metals have low ionization energies; valence electrons are not strongly bound to their parent atoms. Metallic bonding Solo (unbonded) metal atom • A metal is like a fixed lattice of positive ions in a sea of free electrons

  11. Ionic Bonds • Occurs between a metal and non-metal. • Happen when one or more electrons are transferred between atoms. • Causes one atom to become positive, and one to become negative. • The oppositely charged ions are now attracted to each other.

  12. +1 –1 Cl Na Sodium ion Chloride ion 1 electron Ionic bond Cl Na Sodium atom Chlorine atom In ionic compounds, electrons are NOT SHARED but TRANSFERRED.

  13. Ionic Bond Example:

  14. 1 electron 1 electron +2 –1 Mg –1 Chloride ion Cl Cl Chloride ion Magnesium ion Ionic bond Ionic bond Chloride atom Chloride atom Mg Cl Cl Magnesium atom In ionic compounds, electrons are NOT SHARED but TRANSFERRED. Magnesium chloride (MgCl2) is also an ionic compound.

  15. Covalent Bonds • Occurs between 2 non-metals. • When electrons are shared between atoms to fill the outer shell of each. • As 2 atoms approach each other, each nucleus begins to tug on the other’s electrons. Eventually, the orbitals overlap, forming a covalent bond.

  16. Covalent Bond Example:

  17. Covalent bonds A chemical bond is formed by sharing or transferring electrons. There are two covalent bonds in a water molecule. covalent bond: a chemical bond that consists of two shared electrons. molecule: a neutral group of atoms bonded together by covalent bonds.

  18. Polar Covalent Bonds • In polar bonds, electrons are not shared equally between the atoms. • Occur when there is a large difference in electronegativity. • As a result, polar bonds have dipoles (positive and negative ends).

  19. Non-Polar Covalent Bonds • When there is little difference in the electronegativity. • Electrons are equally shared between the atoms.

  20. Multiple bonds Single bonds Double bond Triple bond Some elements can share multiple electrons with the same atom.

  21. Determining Polarity • Electronegativity and ionization energy determine polarity.

  22. Polar and Non-Polar Bonds • 4.0 – 4.0 = 0 • Non-Polar Bond • 4.0 – 2.1 = 1.9 • Polar Bond

  23. In the diagram to the right, the arrow shows which way the shared electrons are being pulled in the polar bond. • The q+ and q- indicate the partial positive and negative ends of the molecule. q+ q-

  24. Determining if a Molecule is Polar • If all bonds in the molecule are non-polar, then the whole molecule is non-polar. • If there are polar bonds, but there is symmetry in the molecule, then the molecule is non-polar. • If there are polar bonds, but there is no symmetry, the molecule is polar.

  25. Carbon Dioxide Each C-O bond is polar, however the symmetry of the molecule leads to the bonds cancelling each other out. Therefore, CO2 is a non-polar molecule.

  26. Water Each O-H bond is polar, and the molecule is not symmetrical, so water is a polar molecule.

  27. Molecular Geometries When all attached atoms are the same…

  28. Valence Electrons and Bonding Patterns • Only unpaired valence electrons bond. • In a molecular compound, each unpaired electron can form one covalent bond.

  29. Learning Check • Which electrons are involved in bonding? • What is the difference between ionic and covalent bonds? • What determines polarity? • Hydrogen and Carbon bond together. What kind of bond is this? • Sodium and Fluorine bond together. What kind of bond is this? • How many bonds does Potassium make? • How many bonds does Aluminum make? • How many bonds does Sulfur make? • How many bonds does Neon make?

More Related