17.8 - Electrons in the Atom

Group Ft. ~

[ANOTHER SPAM JOURNAL FILLED WITH NOTES, PLEASE IGNORE]

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Ion: An atom with a net electric charge, which is due to a loss or gain of electrons. 
Shell Model of the Atom: A model in which the electrons of an atom are picture as grouped in concentric shells around the nucleus. 
Periodic Table: A chart that lists elements by atomic number and by electron arrangements, so that elements with similar chemical properties are in the same column. 
Group: Elements of the same column of the periodic table. 

Electrons are negatively charged subatomic particles. They are about 1800 times less massive than a proton or neutron. Electrons do one significantly contribute to the mass of an atom. Ina neutral atom the number of electrons matches the number of protons. Atoms will want to balance themselves out. When an atom has more or less electrons then protons the atom has a net charge and is called an ion. It is the attraction between electrons and protons that bonds atoms together;
A Covalent Bond - happens when electrons are shared between atoms. 
An Ionic Bond - happens when atoms trade electrons. 

The farther apart the atoms are in the periodic table, the more likely the bond will be ionic.
An atom is mostly empty space. The electrons form a kind of cloud around the nucleus. It takes a huge amount of energy to compress this cloud around the nucleus. 

Elements are arranged in the periodic table into rows that match these energy levels. The energy levels can hold the following number of electrons. 

The arrangement of the electrons in shells about the atomic nucleus dictates such properties of a substance as;
-Conductivity
-Taste
-Melting & Freezing Point
-Texture
-Color

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