Chlorine has two isotopes: 25% is chlorine-37 75% is chlorine-35 Chlorine-37 25X37=925 Chlorine-35 75X35=2625 925+2625=3550 3550/100=35.5
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What is an ion
An atom that has gained or lost an electron
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What type of metals do ions form
Positive metals
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What type of non-metals do ions form
Negative non metals
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Surface area to volume ratio
A cube shaped nanoparticle has sides of 10nm. Calculate its surface area to volume ratio. surface area=6X(10X10)=600nm2-Cubes have six sides Volume=10X10X10=1000nm3 Surface area to volume ratio=600nm2/1000nm3=0.6
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What are polymers
Giant molecules that form plastics
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What does ionic bonding do
Steals electrons to form compete ions
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What does covalent bonding do
Shares electrons to form compete ions
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What does metallic bonding do
The spare electrons in the outer shells are free to move in an area of delocalisation
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Are covalent bonds conductive
No as they are formed of non-metals and share out electrons
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Are ionic bonds conductive
Only when they are in an aqueous solution or in their aqueous form as the ions are free to move
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Why are metals malleable
Metallic bonding forms layers. These layers which can slide over each other.
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Why does this rule not apply to alloys.
The layer formation in alloys is distorted
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Do giant covalent substances have a high melting/boiling point?
Yes as the covalent bonds are strong
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Do simple covalent substances have a high melting/boiling point?
No as they have weak intermollecular forces between molecules
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Do giant ionic substances have a high melting/boiling point?
Yes as they have strong electrostatic forces of attraction
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Do metallic substances have a high melting/boiling point?
Yes as they have strong electrostatic forces of attraction
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