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12 Cards in this Set
- Front
- Back
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what are the particles of the nucleus in an atom? |
Protons and neutrons |
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explain why atoms are neutral. |
Atoms have an equal amount of positively charged protons and negatively charged electrons. |
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What is an isotope? |
An element that has atoms with the same atomic number but different masses. |
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Describe how the elements are arranged on the periodic table. |
Atomic number order. In the groups numbered with the number of electrons in the outside shell. In periods in order of how many shells the electrons are occupying. |
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Explain why lithium forms a positive ion. |
Atoms are stable when they have a full outer shell of electrons. Lithium has one electron in its outer shell so is more stable is this electron is lost. This leaves the atom with a positive charge, |
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Explain why fluorine forms a negative ion. |
Fluorine has an electron pattern of 2.7 so needs one more electron to make it stable, making it negatively charged. |
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Explain how the ionic bonding in lithium fluoride means that it becomes solid. |
The positive ions of lithium are attracted to the negative ions of fluorine; to make a giant ionic lattice which is stable. |
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Describe the structure of magnesium oxide. |
Giant ionic lattice. |
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When is magnesium oxide able to conduct electricity? |
When it's molten or in a solution. |
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Explain why a solution of sodium chloride can conduct electricity. |
It contains ions, these are free to move around. |
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Explain why sodium chloride has a high melting point. |
A lot of energy is needed to break apart the giant ionic lattice formed by strong attraction of ions. |
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Explain why magnesium oxide has an even higher melting point that sodium chloride. |
Magnesium transfers out two electrons not just one; magnesium ions are very small so they can get closer so the bonds are stronger. |
