1. Density Density of an object is defined as the object’s mass per unit volume Formula

2. Density Continued… Density is unique to each substance! Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging Regular Solids vs. Irregular Solids

3. Periodic Table Adapted from: http://www.chem4kids.com/files/elem_pertable.html

4. Who is the creator of the P.T.? Dmitri Mendeleev in 1869 Revised by Henry G.J. Moseley

5. Organization Left is the lighter metals, then the heavier metals, then the Non-metals Elements on the borderline between metals and non-metals are called metalloids

6. Organization Horizontal rows called periods – Same number of electron shells

7. Organization Vertical columns called groups – Group 1: Alkali Metals – Group 2: Alkaline-Earth Metals – Group 7: Halogens – Group 8: Noble Gases – Middle: Transition Elements

8. Organization Families Stick Together We just covered the columns and rows of the periodic table. There are also other, less specific, groups of elements. These groups are all over the table. Scientists group these families of elements by their chemical properties. Each family reacts in a different way with the outside world. Metals behave differently than gases, and there are even different types of metals. Some elements don't react, while others are very reactive, and some are good conductors of electricity.

9. Metals 75% of the Periodic Table is classified as a metal – Conduction (conduct electricity) – Reactivity (form compounds) – Chemical (make OH - in a solution) – Alloys (mixtures of metals)

10. Atomic Number Now we're getting to the heart and soul of the way the Universe works. You know that a generic atom has some protons and neutrons in the nucleus and some electrons zipping around in orbitals. When those pieces start combining in specific numbers, you can build atoms with recognizable traits. If you have eight protons, neutrons and electrons, you will have an oxygen (O) atom. If you have seven protons, neutrons, and electrons, you will have a nitrogen (N) atom. The atoms for each element are unique, even though they are all made of similar subatomic parts.

11. Atoms…FYI Remember that 'atom' is the general term. Everything is made of atoms. The term 'element' is used to describe atoms with specific characteristics. There are almost 120 known elements. For example, you are made up of billions of billions of atoms but you probably won't find more than 40 elements (types of atoms) in your body. Chemists have learned that over 95% of your body is made up of hydrogen (H), carbon (C), nitrogen, oxygen, phosphorus (P), and calcium (Ca).

12. Atomic Number

13. Atomic Mass Number The atomic mass number is the AVERAGE weight of the element based upon relative abundance of the naturally occurring isotopes. Unit: Amu (atomic mass units)

14. Periodic Table Song

15. Forms of Energy

16. Energy of Light

17. Absorption & Emission Energy Different atoms have different number of electrons e -

18. Electromagnetic Spectrum

19. Application Fireworks