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22 Cards in this Set
- Front
- Back
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Dmitri Mendeleev |
Russian chemist Made a table Used triads Listed properties of elements (mass, density, color, melting point, and valence number) |
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Henry Moseley |
English scientist Made a table based on increasing atomic number instead of mass |
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Each element in a group |
Has the same number of valance electrons |
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What affects the way an atom bonds |
Number of valence electrons |
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Metals |
Usually solid at room temp, 80% of elements are metals |
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Metalloid |
Diagonal line of elements. Their chemical and physical properties are intermediate between the two |
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Non metals |
Upper right corner of the table Their chemical and physical properties are different from metals |
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Alkali metals |
Group 1A reacts with water to form alkaline solutions (basic) |
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Alkaline earth metals |
Group 2A very reactive but not as reactive as group 1A |
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Halogens |
Group 7A only need 1 electron to fill their shell, very reactive |
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Noble gases |
Group 8A Noble gases as they have completely filled outer shells, not reactive |
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Periodic Law |
When elements are arranged in order of increasing atomic number |
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Representative elements |
Elements in groups 1,2 and 13-17 Display a wide range of physical and chemical properties |
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Rare earth elements |
30 rare earth elements are located in the lanthanide and actinide series |
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Transition elements |
The 38 elements in group 3-12 Ductile, malleable, conduct electricity and heat Their valence electrons are present in more than 1 shell |
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Periodic table trends |
Atomic radius increases from top to bottom and decreases from left to right Electron affinity increases from left to right and from bottom to top Ionization energy increases from left to right and from bottom to top |
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Diatomics |
Hydrogen, nitrogen, oxygen, fluorine, bromine, iodine |
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Shielding Effect |
In an atom there are attractions between the proton and electron also repulsions between the electron, due to the repulsion, each electron shields or screen the other electrons from the nucleus |
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Electronegativity |
the ability of an atom to attract electrons while in a compound |
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Cation |
Positively charged ion always smaller than the original atom |
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Anion |
Negatively charged particle Usually nonmetals always larger than original atom |
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When does election cloud shrink |
shrinks when the atom loses an electron |
