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Published byMerry Potter Modified over 9 years ago
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With your pair define the following words: Elements, compounds, mixtures and molecules Leave 3 lines below each definition Gallery walk: you have 5 minutes to see what your classmates have written and add anything you like onto your definitions
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At the center of each atom is the nucleus. The nucleus is a cluster of particles called protons and neutrons. Protons have a plus (+) charge, and neutrons are neutral (that is, they don't have a charge). Most of the atom is empty space! Electrons have a minus (-) charge, and so there are enough electrons to balance out the (+) protons. Electrons are so light that they really don't count towards the total weight of the atom.
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Electrons in the atoms, cannot move anyway they wish. They are restricted to levels (n). The first level can hold only two electrons. (ex: H) The second and third level can hold eight electrons (ex: C) Hydrogen Carbon 1n 1p
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16n 16p 17n 17p
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5p 5n
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The columns in the Period Table indicate the amount of Valence electrons. Those are the ones found in the outermost level. These electrons have a very special job... They form bonds!!!!
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http://www.webelements.com/
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1. Search for the elements (Sodium, Calcium, Aluminium, Carbon, Phosphorus, Oxygen, Fluorine and Neon) in the periodic table 2. Create a table to include the following information: 1.Element 2.Symbol 3.Amount of protons, neutrons and electrons 4.Draw the atomic structure for each of these atoms 5.Determine the amount of Valence electrons in each of them
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Ionic bonds Ionic bonds happen when one atom gives at least one electron to another atom. The atom that gets an extra electron ends up with a (-) charge and is called an anion. The atom that gives away an electron ends up with a (+) charge and is called a cation. Now, those (+) and (-) charges have a strong attraction to each other - they sit next to each other and refuse to move. Covalent bonds Covalent bonds happen when two atoms share electrons - kind of like 2 atoms holding hands. Sometimes molecules share more than one pair of electrons. If two pairs of electrons are shared then a double bond is formed, and if three pairs are shared then a triple bond is formed. It is not possible to form a "quadruple" bond!
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Ionic bonds Covalent bonds
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NaF KCl CaO CaS MgCl 2 HCl O 2 H 2 O CO 2 NH 3 CH 4
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