1. Elements & Atoms Physical Science

2. What is matter? Matter is anything that has mass and takes up space... so it is stuff Everything you can see and touch is matter. To figure out if something is matter, ask yourself if it has mass and takes up space For the following 8 things, determine whether they are matter or not: You, air, light, desk, gravity, sound, pencil, kinetic energy

3. What is matter made of? An atom is a small particle that is a building block of matter. All matter is made of atoms. Tomorrow we'll see what atoms are made of and what makes atoms different from each other...

4. What is a substance? A substance is matter with a composition that is always the same. For example, oxygen is a substance. Water is a substance. Sugar is a substance. There are two kinds of substances: elements & compounds

5. Elements & Compounds An element is the simplest type of substance (material made of one kind of atom). An element can't be broken down into anything simpler by ordinary physical or chemical methods. Compounds are mixtures or combinations of elements.

6. What are element symbols? Element symbols are a useful AND universal way to abbreviate the name of an element. A chemical symbol has one, two, or three letters, taken from the name of the element it represents (either English or Latin). The first letter in a symbol is always capitalized and any other letter is always lowercase.

7. Matching – In Notes ELEMENTSYMBOL OxygenHg ZincAl NitrogenCa GoldC MagnesiumO CopperZn AluminumAu CarbonN MercuryCu CalciumMg Match each element on the left to its symbol on the right. Why do you think the symbol is not always the first letter or two letters of the element name? Which symbols were the hardest to match & why?

8. Wednesday, January 23 Bell Ringer: What do you know about atoms? What are the parts of an atom and what do you know about each part?

9. Atoms An atom is divided into two different areas: the nucleus and the electron shells. In the nucleus, you can find protons and neutrons. A proton is a particle that is heavy (for an atom) and has a positive charge. Remember, “pro” means positive. A neutron is a particle that is heavy (for an atom) and has no charge. Remember, “neutr-” means neutral or no charge.

10. Nucleus Protons and neutrons are located in the nucleus of an atom. The atomic number of an atom is the number of protons or electrons in that atom. The atomic mass of an atom is the number of protons + the number of neutrons. What is the atomic number of the atom shown? What is the atomic mass of the atom shown?

11. Electrons Electrons are located outside the nucleus in what are called electron shells. They are light and have a negative charge. You can think of electron shells as a series of rings outside the nucleus. The shell closest to the nucleus has the lowest energy and is called the ground state. The farther away you get from the nucleus, the more energy the electrons have. For a neutral atom, the # of electrons = the # of protons.

12. In-Class Assignment On Atoms You know that atomic # = # of protons or electrons and atomic mass = # of protons + # of neutrons. Use this to fill out your worksheet for 6 elements and TURN IN at the end of class.

13. HW due Thursday Your job for homework is to create an element trading card for one of the following elements. You must include atomic number & atomic mass, number of protons, neutrons, & electrons, discovery information, and important uses. Use the template provided to make your trading card. There is a copy of the periodic table on p. 394-395 in your book that may help. Element choices: Hydrogen, Carbon, Oxygen, Calcium, Sodium, Iron, Lead, Aluminum, Copper, Zinc, Nitrogen, Gold, Mercury

14. After semester 1 finals...

15. Intro to Spectroscopy Spectroscopy is the analysis of light interacting with matter. We are going to look at the emission spectra of different metals in order to help us identify the metal and describe the structure of atoms inside that metal.

16. Prism & Light Waves When white light passes through a prism, it produces a rainbow of colors. When light emitted from an element is passed through a prism, you see specific lines of colors

17. Light Waves Waves travel and transfer energy in an oscillating fashion (they wiggle). The amplitude, y, of a wave describes its height from zero to a crest. The wavelength, λ, of a wave is the distance between crests.

18. Waves & Energy If both waves travel at the same speed, which one would have more complete wave cycles passing a point in a given time interval? Since waves transfer energy, which one has more energy? Higher frequencies have higher energy & lower wavelength. shorter

19. Waves & Energy

20. Why do atoms emit light? An atom has a specific arrangement of electrons in valence shells (like we talked about yesterday). If you add energy to an atom, the electrons will absorb energy, get excited, and move farther away from the nucleus. Electrons LIKE being in their ground state, so they return to the ground state by emitting light (photons). Frequency or color of emitted light is proportional to the energy change of the electron (red light = less energy)

21. HW due Thursday, January 26 Complete the “Wave HW” assignment based on today's notes.

22. Thursday, January 26 Bell Ringer: What does the ladder & marker demo have to do with atoms and light?

23. Emission Spectrum When a glowing gas (like a heated metal in a flame test) radiates energy at specific wavelengths depending on the element(s) present in your sample. The emission spectrum of something shows the energy levels that electrons are jumping down from (each line is a different level). The emission spectrum of a sample is like its fingerprint – unique to that sample.

24. Emission Spectrum DEMO http://phet.colorado.edu/en/simulation/discharge-lamps What do you notice or observe about the emission spectrum of ONE of the elements? Are the lines close together or far apart? Is there just one line or are there many? Compare two of the elements.