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3.1 Bonding
Ionic, Covanlent and Metallic.
Question | Answer |
---|---|
Name the Three types of Bonding: | Ionic, Covalent and Metallic. |
Ionic Bonding is: | The strong electrostatic bonding between oppositely charged Ions, between Metal and Non-Metal. |
Give four features of Ionic Compounds: | High Melting points (High energy required to strong electrostatic forces), Giant Lattice Structure, Brittle (Ions of the same charge come into contact), Conduct Electricity when molten or Dissolved (Ions move freely). |
Explain the trends in Electronegativity: | Increases across period because the shielding remains same, increased nuclear charge which reduces atomic radius. Decreasing down group because the Shielding increases and the Atomic radius increases as the electrons get farther away in outer shells. |
In terms of Electronegativity, State the types of bonds that are formed between atoms: | A difference of <0.5 will give Nonpolar covalent, a difference of 0.5 < e < 1.7 (can get up to 2.0) will give Polar Covalent, and > 2 will be Ionic. |
Why do Ionic Compounds have high melting points? | A lot of energy is required to break the electrostatitc forces between the ions which extend throughout the structure. |
A Covalent Bond is: | A shared pair of electrons between two non metals to form a molecule. The electrostatic forces between the pair of electrons and the nucleus is what holds the molecule together. |
A double Covalent bond is: | Two shared pairs of electrons. |
Why do Molecules (covalent) have low melting points? | Because the strong electrostatic forces only exist between the ATOMS in a molecule, not between the Molecules themselves, making it easy to separate them. |
Why aren't Covalent molecules good conductors of electricity? | Because they have a neutral overall charge as no electrons are actually swapped, no ions exist. So no charged particles to carry current. |
Dative Covalent Bond (Co-ordinate Bonding) is: | When one atoms provides both the electrons (LONE PAIR OF ELECTRONS) to form a covanlent bond (Such as in NH4). |
What is the bond called when one Atom provides both of the electrons for a Covalent bond? | Dative Covalent Bond (Co-ordinate Bonding). |
Electronegativity: | Is the power of an Atom to attract electrons towards itself in a covalent bond. |
Metallic Bonding: | The bonding that occurs between metals when a group of positively charged ions are held in place by a sea of delocalised electrons. |