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32 Cards in this Set
- Front
- Back
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What gases does dry air consist of? |
Element gases -- oxygen, nitrogen and argon Compound gases -- carbon dioxide |
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What are the main gases in the atmosphere and what are their percentages? |
Nitrogen 78% Oxygen 21% Argon 1% Carbon dioxide 0.037% |
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What are the chemical symbols for oxygen, argon, nitrogen and carbon dioxide? |
Oxygen -- O2 Argon -- Ar Nitrogen -- N2 Carbon dioxide -- CO2 |
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What are most non metals and compounds between non metals classed as? |
Molecular |
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What properties do molecular elements and compounds with small molecules have? |
Low melting and boiling points Weak forces of attraction between molecules They are gases at room temperature |
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Do pure molecular compounds conduct electricity and why? |
No, because their molecules are not charged |
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What bonding is between molecules and does it arise? |
Bonding within molecules is covalent and arises from electrostatic attraction between the nuclei of atoms and the electrons shared between them |
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What is the difference between small covalent molecules and covalent bonds? |
Small covalent molecules have weak forces of attraction Covalent bonds are strong in comparison |
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What is the earth's hydrosphere? |
It consists of mainly water with some dissolved compounds called salts It is mainly oceans, seas, lakes and rivers |
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How are crystals in a solid ionic compound arranged? |
In a regular lattice |
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What is ionic bonding? |
Ions in a crystal held together by forces of attraction between oppositely charged ions |
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What are the properties of solid ionic compounds? |
High melting and boiling point Strong bonds Giant 3D structures |
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What happens to ions when an ionic compound dissolves in water? |
The bonds brake apart and forms other bonds and leaves free floating ions causing the solution to be able to conduct electricity |
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How can some metal ions be identified in solution? |
By adding alkali because they form insoluble hydroxides with characteristic colours |
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How can some negative ions in salts can be identified? |
By adding a reagent that reacts with ions to form an insoluble solid |
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What is the earth's lithosphere? |
The rigid outer layer of the earth made up of the crust and the part of the mantle just below it It's made up of a mixture of minerals |
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What are diamond and graphite minerals composed of? |
They are composed of carbon atoms |
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What are the properties of diamond? |
High melting and boiling point Very hard Doesn't conduct electricity |
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How do the properties of graphite differ from diamond? |
It has layers that slide over each other It conducts electricity It has high melting and boiling points |
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What are 3 very abundant elements in he earth's crust? |
Silicone Oxygen Aluminium |
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How does a lot of the silicone and oxygen it he earth's cryst appear as? |
The compound silicone dioxide (quartz) |
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What are ores? |
Rocks that contain varying amounts of minerals from which metals can be extracted |
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Do all minerals only need small amounts of ore mines to recover large percentages of valuable mineral? |
No some minerals need very large amounts of ore to to be mined to recover small percentages of valuable minerals e.g. copper |
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What metals can be extracted by heating their oxides with carbon? |
Zinc Iron Copper |
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What happens to oxygen and carbon during the extraction of metals from their ores? |
Oxygen is reduced Carbon is oxidised |
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Can all metals be extracted from their ores using carbon? |
No, only those less reactive than carbon |
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What do the state symbols (s) , (l), (g) and (aq) mean? |
(s) solid (l) liquid (g) gas (aq) aqueous solution |
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What do electrolytes include? |
Molten ionic compounds |
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What happens to ions when an ionic crystal melts? |
The ions are free to move and can conduct electricity |
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During electrolysis what forms at the negative and positive electrode? |
Positive electrode-non metals Negative electrode-metals |
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What 2 things happen during electrolysis of molten aluminium? |
Positively charged ions gain electrons from the negative electrode to become neutral atoms Negatively charges oxide ions lose electrons to the positive electrode to become neutral atoms which combine to form oxygen molecules |
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What what properties of metals can limit their uses as they vary? |
Strength Malleability Mtp and btp Electrical conductivity |
