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35 Cards in this Set
- Front
- Back
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How many electrons are held in s, p, d, and f orbitals? |
s - 2 p - 6 d - 10 f - 14 |
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Why do ionic compounds have high melting and boiling points? |
The strong electrostatic forces between all the ions in a giant lattice have to be overcome when melting or boiling the substance. |
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Why are ionic substances able to conduct electricity when melted, or dissolved in water? |
because the ions are able to move and carry the charge. |
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What is a lone pair? |
An outer-shell pair of electrons that is not involved in chemical bonding. |
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What is a dative covalent bond? |
One of the atoms supplies both the shared electrons to the covalent bond. Once formed dative covalent bonds are equivalent to ordinary covalent bonds. |
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What is Relative isotopic mass? |
the mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12. |
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What is Relative atomic mass, Ar? |
Ar, is the weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12. |
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What is mass spectometry? |
A mass spectrometer allows you to find the relative abundance of each isotope of an element. |
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What are Van der Waals' forces? |
Several different kinds of intermolecular bonding: - dipole-dipole interactions. - London (dispersion) forces - Important (not hydrogen bonds) |
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What are Hydrogen bonds? |
A hydrogen bond is a strong permanent dipole-permanent dipole attraction between: - an electron-deficient hydrogen atom (O-H+, N-H+, or F-H+) on one molecule; and - a lone pair of electrons on a highly electronegative atom (O, N, or F) on a different molecule. |
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What is an intermolecular force? |
an attractive force between neighbouring molecules |
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What is a permanent dipole-dipole interaction? |
A weak attractive force between permanent dipoles and permanent dipoles or induced dipoles in a neighboring polar molecules. London (dispersion) forces are attractive forces between induced dipoles in neighbouring molecules. |
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What is a permanent dipole? |
The small charge difference across a bond that results from a difference in the electronegativities of the bonded atoms. A polar covalent bond has a permanent dipole. |
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What is electonegativity? |
A measure of the attraction of a bonded atom for the pair of electrons in a covalent bond. |
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How much does a lone pair reduce the bond angle by? |
about 2.5 degrees. |
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Name 3 laboratory acids and their formula: |
- sulfuric acid, H2SO4 - hydrochloric acid, HCl - ntiric acid, HNO3 |
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What is the atomic number? |
The number of protons in the nucleus |
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What is a period in the periodic table? |
The horizontal row. The atomic number increases along the period. |
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What are groups in the periodic table? |
Each vertical column is called a group, and it shows patterns in chemical and physical properties. Chemical reactions involvr electrons in the outer shell. Elements in groups have atoms with the same number of electrons in their outer shells - which explains their similar chemical behaviour. |
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What is periodicity? |
Across each period, elements change from metals to non-metals. As you move down the periods, this change moves further to the right. |
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What is the key exception to remember regarding orbit energy levels? |
The 4s energy level is lower than the 3d energy level, so the 4s orbital fills before the 3d. |
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What is the first ionisation energy? |
The first ionisation energy of an element is the energy required to remove one electron from each atom in one mole of the gaseous element to form one mole of gaseous 1+ ions. |
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What are the three factors nuclear attraction experienced, by an electron, depends on? |
1. Atomic radius 2. Nuclear charge 3. Electron shielding or screening |
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Why do ionisation energies generally increase along a period? |
1. The number of protons in the nucleus increases, so there is a higher attraction on the electons. 2. Electrons are added to the same shell, so the outer shell drawn slightly inward. 3. There is the same number of inner shells, so electron shielding will hardly change. |
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Why do first ionisation energies decrease down a group? |
1. The number of shells increases, so the distance of the outer electrons from the nucleus increases; so, there is a weaker force of attraction on the outer electrons. 2. There are more inner shells, so the shielding effect on the outer electrons from the nuclear charge increases; so, again there is weaker attraction. |
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What is ^ (triangle) symbol on an equation... |
It means heat applied |
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What does diatomic mean? |
It is in reference to gases, which except for the noble gases, exist in diatomic molecules.. e.g. H2 |
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All nitrates are... |
Soluable! |
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What are 3 properties of giant metallic lattices? |
1. High Melting and Boiling Points 2. Good electrical conductivity 3. Malleability and ductility |
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OILRIG |
Oxidation is loss.. Reduction is gain.. |
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What does .xH20 mean? |
Water of crystallisation. Anhydrous is without water. Hydrated would be MgSO4.7H2O, and is a hydrated salt |
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What is average bond enthalpy |
The mean energy needed for 1 mole of a given type of gaseous bonds to undergo homolytic fission. |
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Factors that affect reaction rates |
Temperature Pressure Concentration Surface area Adding a catalyst |
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Collision Theory |
Concentration: Increased concentration gives more molecules in the same volume. The molecules will be closer together therefore there is a greater chance of them colliding. Pressure: Same number of molecules occupy a smaller volume. The molecules will be closer together therefore greater chance of them colliding. |
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Boltzmann Distribution |
The Boltzmann Distribution is the distribution of energies of molecules at a particular temperature, often shown as a graph. |
