1. Periodic Table Notes Feb 16 Write everything in black font

2. Atoms-are the smallest building blocks of matter, they cannot be created, destroyed or divided. Exception: Atoms can be split by nuclear reactions and created in labs

3. Structure of Atoms In neutral atoms the # of protons in the nucleus equals the # of electrons, but the neutrons can be different If the atom is charged (lost/gained some e-), it is called an ION (Example Na+ ions) p p p p p p Protons (p+) Neutrons (n 0 ) Nucleus Electrons (e-) Shell 5 5 4

4. Different Elements have atoms with their own unique number of protons and electrons Oxygen has 8 protons How many electrons? 8 electrons Oxygen also has 8 neutrons p p p p p p p p One element might have some atoms with more neutrons than others – ISOTOPES Some carbon atoms have 8 neutrons, some have 6 neutrons – Carbon-14 and Carbon-12 are used for carbon dating

5. Atoms combine to make compounds and molecules Water – H 2 O 1 Oxygen 2 Hydrogens Sugar – C 6 H 12 O 6 Nitrogen in the air – N 2

6. History of the Table -Back in the 1800s, scientists started to notice patterns in the properties of the elements. -Mendeleev then was able to predict the properties of elements that had not yet been discovered. -In 1860, Dmitri Mendeleev organized the known elements based on these patterns to make the first periodic table.

7. The Periodic Table: A way of arranging the elements based on patterns that are seen in their properties. When elements have similar properties, they are placed in the same column on the table.

9. Groups: The columns on the periodic table. Elements in the same group have similar properties. Example: Group 1 elements all react violently with water. Group 18 elements do not react with anything and are gases

10. Periods: Rows on the periodic table. Elements in the same row have very different properties. They are lined up by atomic number in the rows. Example: Xenon which is a gas that doesn’t react with anything is in the same period as Rubidium which will cause an explosion in water.

12. How to read the Periodic Table B Boron 10.811 5 Atomic Symbol Element Name Atomic Mass Atomic Number

13. What do the numbers mean? B Boron 10.811 5 Atomic number: how many protons are in the nucleus and how many electrons the element has. Atomic mass: how much the atom weighs and 5 protons 5 electrons 6 neutrons Mass - atomic# = #of neutrons

14. Abbreviations – it’s a matter of life and death: One capital letter or a capital and a lower case – you MUST follow this rule CO is a compound called carbon monoxide that kills you Co is an element called cobalt that is part of essential vitamins

15. Practice Problems: For each of these elements, identify how many p+, e- and n 0 it has and name one other element that has similar properties 1.Sodium 2.Calcium 3.Carbon 4.Neon 11p+, 11e-, 12n 0, Potassium/Lithium/etc.