Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
You can change this under Settings & Account at any time.
Transcript of CHEMICAL BONDING
Sodium (Na) loses its valence electron to Chlorine (Cl), leaving both Cl (2,8,8) and Na (2,8) with 8 electrons in the outermost shell.
Ionic bonds take place between metals and non-metals.
They take place between two atoms that have a large difference in electronegativity.
They are formed when there is a complete transfer of electrons from one atom to another. This means at the end one atom will be negatively charged (an anion) and the another one will be positively charged (a cation).
These opposite charges are what hold the two atoms together, and thus they form an ionic bond. Ionic compounds must be electrically neutral, that is their net positive and negative charges should cancel.
Both Hydrogen (H) atoms share their electron, in order to complete their outer shells. Both atoms now have 2 electrons in their outermost shell.
Covalent bonds take place between atoms which have equal or close electronegativity.
The two atoms share their electrons in order to satisfy the octet rule.
There are 2 types of covalent bonds - pure covalent bonds and polar covalent bonds.
PURE COVALENT bonding takes place if the atoms are equally electronegative; both have the same tendency to attract the bonding pair of electrons, and so they will be found on average half way between the two atoms.
A Polar Covalent Bond takes on both aspects of an Ionic Bond and a Covalent Bond.
This type of bonding takes place when there is a moderate difference between the electronegativity of two atoms, but they do not surpass 1.7
The electrons are shared but one element attracts them more strongly than the other. In the resulting polar covalent bond, a partial positive and partial negative charge is created at the poles of bond thus giving the Covalent Bond some Ionic or Polar properties.
COMPOUNDS & ELECTRONS
The type of bond seen in elements and compounds depends on the chemical properties as well as the attractive forces governing the atoms and molecules.
In each type of bonding, the compound created fulfills the need to satisfy the octet rule, that is the valence electrons on the outer shell are either lost or gained in order to complete the shell.
Metals normally lose ions, whilst non-metals gain electrons in order to have a full outer shell.
GROUP I AND GROUP VII
The bonding between elements from Group 1 and 7 on the periodic table is ionic.
Group 1 has an excess of one electron, it needs to lose this one electron in order to be a noble gas (complete octet rule).
Group 7 has seven electrons on the outer shell and needs one electron in order to become a noble gas.
So the excess electron (Group 1) gets added to the seven electrons (Group 7) and both elements become noble gases.
High boiling point
High melting point
Soluble in water
Conduct electricity when melted or dissolved (the lattice breaks up and ions are free to move)
Low boiling point
Low boiling point
Less soluble in water
Compounds are not charged, thus cannot conduct electricity
} More volatile
} Less volatile
Metallic bonding holds together the particles in a metal.
Metallic bonds are strong and a lot of energy is needed to break them.
This is why metals have high melting points and boiling points.
Metals contain electrons that are free to move in the metal structure, carrying charge from place to place and allowing metals to conduct electricity well.
Giant covalent structures contain a lot of non-metal atoms, each joined to adjacent atoms by covalent bonds.
The atoms are usually arranged into giant regular lattices - extremely strong structures because of the many bonds involved.
Substances with giant covalent structures have very high melting points, because a lot of strong covalent bonds must be broken. Example: Diamond, Graphite
The amount of energy required to break apart a mole of molecules into its component atoms is called bond dissociation energy or simply bond energy. Bond energies can be used to understand the strength of a bond
To estimate the enthalpy (heat content) changes in chemical reactions and to predict whether the reactions are exothermic or endothermic.
TYPES OF CHEMICAL BONDS
WHAT IS BOND ENERGY?
The electrons although shared are not equally shared in a polar covalent bond.
POLAR COVALENT bond
Electrons are approximately half way between the two atoms.
PURE COVALENT bond
Covalent networks (giant structures) are insoluble in water.