Post on 03-Jan-2016
Let’s Talk Chemistry!
1. The Atom
basic unit of matter made up of protons, neutrons and
electrons the atom is neutrally charged (no charge)
Helium Atom: Atomic Number 2
Electron
Proton
Neutron
2. Structure of an atom2. Structure of an atom
The nucleus of an atom:The nucleus of an atom: Protons are positively charged
Neutrons have no charge
Electrons: in constant motion around nucleus negatively charged
Atoms have an equal number of Atoms have an equal number of protons and electrons.protons and electrons.
3. Elements3. ElementsPure substancePure substanceMade of one type of atomMade of one type of atomRepresented by 1, 2 or 3 lettersRepresented by 1, 2 or 3 letters
4. History of the Periodic Table4. History of the Periodic Table
Mendeleev designed the first periodic table
He arranged the elements by increasing atomic mass
He left blank spaces according to similarities in columns of elements
More history…More history…
Mendeleev’s blank spaces (or predictions) were elements that he claimed were not discovered yet.
As it turns out, he was right!!
Scientists later discovered the missing elements with the properties that Mendeleev predicted!
And even more history!And even more history!Moseley discovered the atomic
number
He organized the periodic table by increasing atomic number
This allowed for elements with similar properties to fall into place
An gave way to the modern periodic table
5. Molecules5. Molecules
Smallest unit (part) of a compound Hydrogen molecule
Water
6. Compounds6. Compounds a substance that contains two or
more different elements
organic compounds must contain Carbon
Acetic acid
7. Molecular formulaMolecular formula
Shows how many atoms of each Shows how many atoms of each
element a molecule containselement a molecule contains
Does not tell you about a molecule’s Does not tell you about a molecule’s structurestructure
Examples of molecular Examples of molecular formulasformulas
HH22OO 2 hydrogen2 hydrogen1 oxygen1 oxygen
NHNH33 1 nitrogen1 nitrogen3 hydrogen3 hydrogen
CC66HH1212OO6 6 6 carbon6 carbon12 hydrogen12 hydrogen6 oxygen6 oxygen
8. Structural formula8. Structural formula
Shows how atoms are arranged in a Shows how atoms are arranged in a moleculemolecule
2-dimensional representation of a 2-dimensional representation of a molecule’s structuremolecule’s structure
9. 3-D model9. 3-D model
Shows how the atoms are arranged in a molecule
Is able to be moved or turned, allowing you to view the molecule from different angles
3D model