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29 Cards in this Set
- Front
- Back
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What are noble gases? |
Inert elements in group 0. They are very stable and exist on their own. |
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Why are noble gases stable? |
They have 2 or 8 electrons in their outer shell. |
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What is the octet rule? |
Except for the noble gases, atoms chemically combine with each other so that each atom has 8 electrons in its outer shell. |
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What are the two ways of achieving the octet rule? |
Transferring electrons from one atom to another (ionic bonding) Sharing pairs of electrons (covalent bonding) |
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What are the three types of bonding? |
Covalent Ionic Metallic |
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What is ionic bonding? |
Electrons are transferred from the metal to the non-metal. This forms compounds consisting of oppositely charged ions and there is electrostatic attraction between oppositely charged ions. |
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What is covalent bonding? |
A pair of electrons are shared between atoms (electrons localised between nuclei). Occurs in compounds of non-metals There's a strong electrostatic attraction between the shared pair of electrons and the nuclei of the bonded atoms. |
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What is metalic bonding? |
Consists of a lattice of positive metal ions attracted to a sea of delocalised electrons which are shared. |
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Define ionic bonding |
The electrostatic attraction between oppositely charged ions. |
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What is the overall charge of an ionic compound? |
Neutral because the opposite charges cancel each other out. |
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Define covalent bonding |
The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms. |
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What happens when a covalent bond forms? |
Each atom provides one electron to be shared. The pair of shared electrons are attracted to the nuclei of both bonding atoms, creating a bond. |
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What is a lone pair of electrons? |
Pairs of electrons in the outer shell of an atom which are not involved in covalent bonds (regular electrons) |
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What is a single covalent bond? |
The sharing of one pair of electrons between two atoms. |
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What is a multiple (double or triple) covalent bond? |
This is the sharing of 2 or 3 pairs of electrons between 2 atoms. |
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What symbol is sometimes used to portray a shared pair of electrons? |
A dash
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How can the octet rule be broken? |
Octet expansion Orbital hybrids Democracy principle-energy incentive |
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What happens in octet expansion? |
They can form more bonds than they need |
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Which elements can undergo octet expansion? |
Those in period 3 |
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Which will be the central atom in a compound with 3 or more elements? |
The atom which needs to form the most bonds. |
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What is dative covalent (coordinate) bonding? |
The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms, where only one of the atoms supplies both of the electrons shared. |
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What is the shorthand notation for a dative covalent bond? |
An arrow which points to the receiver of the lone electrons. |
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What is average bond enthalpy> |
This can be used as a measurement of covalent bond strength. |
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What does a large value of bond enthalpy mean? |
A large bond strength |
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When is energy needed? |
When a bond is broken |
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What is this type of reaction? |
Endothermic |
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When is energy released? |
When a bond is formed |
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What is this type of reaction? |
Exothermic |
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What does a plus sign show? |
Energy going in to break a bond. |
