AND OTHER SMALL STUFF

Transcription

1 The Atom AND OTHER SMALL STUFF

2 What is an atom???? atom: a small particle that is the basic unit of matter The smallest piece of an element that represents that element. Atoms are made of PROTONS, NEUTRONS, and ELECTRONS. Atoms are VERY SMALL. Individual atoms can be seen with a scanning tunneling microscope. This was first done in 1981.

3 What is inside an atom? proton: an atomic particle with one positive charge neutron: a neutral atomic particle Both the proton and the neutron are found in the nucleus at the center of the atom. This is were most of the mass is found. electron: an atomic particle with one negative charge Electrons are found in the electron cloud around the nucleus. Most of the inside of an atom is EMPTY SPACE.

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5 What are elements? element: a substance that consists of just one type of atom The type of atom is determined by the number of protons it has. This determines the element. If the atom is NEUTRAL then the number of electrons is equal to the number of protons.

6 How are elements described or identified? The number of protons in the atom determines the element. atomic number: the number of protons in an atom of an element atomic mass: the sum of the protons and neutrons in an atom atomic symbol: the letter or letters representing the element

7 T H E AT O M S FA M I LY WA S C R E AT E D B Y K AT H L E E N C R AW F O R D, P R E S E N TAT I O N D E V E L O P E D B Y T R A C Y T R I M P E, , H T T P : / / S C I E N C E S P O T. N E T /

8 The Atoms Family Story In the center of Matterville, there is a place called the Nucleus Arcade, where two members of the Atoms Family like to hang out. Perky Patty Proton, like her sisters, is quite large with a huge smile and eyes that sparkle (+). Patty is always happy and has a very positive personality. Nerdy Nelda Neutron is large like Patty, but she has a boring, flat mouth and eyes with zero expression (o). Her family is very apathetic and neutral about everything. Patty, Nelda, and their sisters spend all their time at the arcade. Name: Patty Proton Description: Positive Favorite Activity: Hanging out at the Nucleus Arcade Name: Nelda Neutron Description: Neutral Favorite Activity: Hanging out at the Nucleus Arcade

9 Around the Nucleus Arcade, you will find a series of roadways that are used by another member of the Atoms Family, Enraged Elliott Electron. Elliott races madly around the Arcade on his bright red chrome-plated Harley-Davidson. He rides so fast that no one can be sure where he is at any time. Elliott is much smaller than Patty and Nelda and he is always angry because these bigger relatives will not let him in the Arcade. He has a frown on his face, eyes that are squinted with anger, and a very negative (-) attitude. Name: Elliott Electron Description: Negative Favorite Activity: Racing around the arcade

10 The first energy street can only hold only two Electron brothers. The second energy street, called the Energy Freeway, can hold 8 brothers. The third energy street, called the Energy Superhighway, can hold 18 of the brothers. Energy Superhighway Can hold 18 electrons Energy Freeway Can hold 8 electrons Energy Street Can hold 2 electrons Nucleus Arcade Contains protons & neutrons

11 The morale of Matterville is stable as long as each negative Electron brother is balanced out by one positive Proton sister. The number of residents in Matterville depends on the Proton and Neutron families. Challenge: What would happen to the morale of Matterville if one Elliott Electron was kidnapped?

12 Challenge 2: What would happen to the morale of Matterville if one Elliott Electron moved to Matterville?

13 The Periodic Table Dimitri Mendeleev: Russian scientist and inventor; Father of the Modern Periodic Table Grouped elements of similar properties together Left gaps in the table for future discovery of then unknown elements ROWS called PERIODS, there are 7 horizontal periods COLUMNS called GROUPS or FAMILIES, there are 18 groups

14 The Periodic Table con t The atomic number identifies an element Each element has a unique number of protons Moving from left to right and top to bottom on the periodic table, the number of protons increases by one. A row is called a PERIOD because the properties of elements in a row follow a repeating (periodic) pattern as you move across each period.

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16 Elements Pure substances are made of only one kind of atom. When writing the atomic symbol for an element, always capitalize the first letter. If there is a second letter, it is always lower case. Examples Oxygen Gold O Potassium K Chlorine Au Cl

17 Metals Metals are located to the left of the transition (zigzag) line. Metals are -ductile: to be pulled into a thin wire (like copper) -malleable: hammered into a thin sheet (like aluminum) -conduct heat and electricity Alkali Metals: Group 1: Li, Na, K, Rb, Cs, Fr (NOT H) Alkaline Earth Metals: Group 2: Be, Mg, Ca, Sr, Ba, Ra Transition Metals: Groups 3-12, Lanthanides, and Actinides

18 Nonmetals Nonmetals are located to the right of the transition (zigzag) line. The properties of nonmetals are opposite of metals. Some nonmetals such as carbon can exist in different forms (diamond, graphite, and charcoal) based on the environmental conditions in which they are created. C, N, O, P, S, Se All of the HALOGENS: Group 17: F, Cl, Br, I These are elements that react with metals to form salts (NaCl)

19 Metalloids Metalloids border the transition (zigzag) line on the periodic table. They have properties of both metals and nonmetals. They make semiconductors- they conduct electricity at high temperatures, but not at low temperatures B, Si, Ge, As, Sb, Te, Po, At

20 Group 18: NOBLE GASES Noble gases which are usually nonreactive They have 8 electrons in their valence shell, except for He. He, Ne, Ar, Kr, Xe, Rn