Daniel Radcliffe sings The Element's Song.mp4 Vin Diesel on Helium.mp4. Periodic Table

Transcription

1 element song.mp4 Daniel Radcliffe sings The Element's Song.mp4 Vin Diesel on Helium.mp4 Mythbusters on Helium Very Funny Video.mp4.mp4 Periodic Table Periodic Table: a visual representation which organizes the elements by chemical and physical properties. Atoms are organized in the periodic table according to certain patterns in their properties. Atomic #: at the top of each element's square in the periodic table, it tells us the # of protons the element has. # of protons (positive) = # of electrons (negative) Symbol: letter which represents the element. 1

2 Metals, non metals and metalloids: Elements are also divided by a staircase on the periodic table which separates the metals, nonmetals and metalloids. 2

3 Metals On the left (except hydrogen) Conduct heat and electricity Ductile (shaped into wires) Malleable (bendable) Shiny (metallic lustre) Soft (can be cut with a knife) Solid at room temperature, except Mercury React with acid and water High melting point 3

4 Non Metals To the right of staircase Do not conduct heat or electricity Can be solids, liquids or gases Opposite properties of metals ex. not good conductors 4

5 Metalloids Found surrounding the staircase Have properties of both metals and nonmetals Example, they may be malleable but does not conduct 5

6 Families of the Periodic Table (Groups) Vertical column (up/down) Are elements in the same column Hydrogen is not in any group Have similar chemical properties Have the same # of valence electrons Group # = # of valence electrons Valence Electrons: Are the electrons on the outer most energy level (orbit) 6

7 Group IA Alkali Metals (except hydrogen) Soft React with air and water Stored in oil NEVER found as an element in nature Always found as compound in nature Most reactive family because it only has one valence electron Get MORE reactive as you go DOWN the column All have 1 electron on last shell 7

8 Group IIA Alkaline Earth Metals Same properties as alkali metals, but slightly less reactive Get MORE reactive as you go DOWN the column All have 2 electrons on last shell 8

9 Group VIIA Halogens Same characteristics as non metals Form salts when combined with alkali metal (Halogen + Metal = salt) ex. NaCl Form acids when combined with H ex. HCl Used as disinfectants ex. Chlorine Get more reactive as you go UP the column All have 7 electrons on last shell 9

10 Group VIIIA Noble Gases (Inert Gases) Stable (react minimally), because electron shells are full If electricity is passed through they give off a bright light He is part of this group because it's outer shell is full All have 8 electrons on outer shell (except Helium) *Families 3 6 are named after the first element in the group. For example, group 3 is called the boron group. Comparing the four halogens (28).mp4 Brainiac Alkali Metals.mp4 Francium Bomb in Ocean.mp4 Huge Chunk of Sodium in Pond.mp4 Group 2 Reactions with water Periodic Properties.mp4 10

11 Group 1 Alkali metals Periods Group 2 Alkaline Earth metals Metals Group 7 Halogens Non metals Metalloids Group 8 Noble Gases 11

12 Periods, orbits, energy shells or energy levels: Periods of the Periodic Table Period horizontal row of the table (left/right) elements in the same period have the same # of energy levels (orbits) The period # = # of energy levels(shells/orbits) 12

13 Lewis Diagrams Is a simplified representation of the atom, in which only Valence Electrons (v.e.) are drawn represented using dots. The group # = # v.e.= # of dots All elements in the same group have the same Lewis notation. Exception: Helium in group VIIIA only has 2 dots NOTE: Dots are placed at the 4 compass points (N, E, S and W) around the element symbol. You cannot double up on a compass point until each point has a dot. No compass points should have more than 2 dots. 13

14 Lewis Diagrams for each group of the periodic table 14

15 Examples: Na Mg Al C P O Cl Ne 15

16 * Normally, atoms are neutral (# protons= # electrons). (Protons are positive, electrons are negative so the charges cancel each other out and atom is neutral) Atoms of most elements tend to bond with other elements to form molecules. They then become more stable because the orbit furthest from the nucleus is complete (like that of the noble gases). 16

17 Ions: An atom that has become electrically charged by gaining or losing an electron. An atom that is no longer electrically neutral is called an ion. *When an ion is formed, the # of protons is unchanged which preserves the nature of the element. **Only the # of electrons change** Atoms react to achieve noble configuration (become stab because they have a full outer shell) Atoms can give away electrons (metals) or gain electrons (non metals) If an atom gives away electrons, it becomes positively charged (more protons than electrons) If an atom gains electrons, it becomes negatively charged (more electrons than protons) 17

18 EX: Sodium (Na) is in group 1 and has 1 valence electron, so it would likely bond with an element in group 7 with 7 valence electrons like Chlorine (Cl)! This gives us table salt (NaCl)!! 18

19 Tendencies to lose/gain electrons The group # helps us determine whether the element tends to lose or gain electrons!! Ionic Charge (Valence #) Groups 1, 2, 3, 4 form + ions (+1, +2, +3, +4) because they give away electrons to become stable Groups 5, 6, 7 form ions ( 3, 2, 1) because they gain electrons to become stable (8 group number = ionic charge) Group 8 does not form ions, they do not react! This is because their orbit is already full and stable with 8 electrons. 19

20 Examples of Ions Group 1: Na Group 5: N Group 2: Mg Group 6: O Group 3: Al Group 7: F Group 4: C Group 8: NO IONS 20

21 Ions can be positively charged or negatively charged! Group 1 Group 2 Group 3 Group 4 Loses 1 (+1) loses 1 or more electrons to non metals, it forms a positive ion and has a positive charge (more protons then electrons) Group 5 Group 6 Group 7 gains 3 ( 3) gains 1 or more electrons from metals, it forms a negative ion and has a negative charge (more electrons then protons) Group 8 Does not form ions. Why? Becuase their orbits are full and are therefore already a stable atom. 21

22 Past exam questions 1. Fill in the table below. Element Br Ca Na Ne Number of Chemical Family Valence Electrons Name 2. Four elements from the periodic table are described below. Element 1 Element 2 Element 3 This element from Period 2 has two more electrons than helium. This soft metal from Period 3 has one valence electron. This element from Period 4 is found in bones and teeth. This element from Period 3 has some of Element 4 the properties of metals and non metals. Which of these elements belong to the same group or chemical family? A) 1 and 2 B) 1 and 3 C) 2 and 4 D) 3 and 4 3. The table below provides certain information about the symbol, the electron configuration, the name of the chemical family and the period number of four elements in the periodic table. Symbol Electron configuration Mg Name of the Period chemical number family Alkali metals 2 )2e )3e )2e Fill in the table above. 22

23 Past exam questions 1. Which atom is correctly represented with the Lewis notation? 2. During ionization, an atom can become a positive ion. How does an atom become a positive ion? A) It gains one or more electrons B) It loses one or more electrons C) It gains one or more protons D) It loses one or more protons 23

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25 Attachments element song.mp4 Mythbusters_on_Helium_ _Very_Funny_Video.mp4 Daniel_Radcliffe_sings_The_Element's_Song.mp4 Vin_Diesel_on_Helium.mp4 Comparing_the_four_halogens_(28).mp4 Francium_Bomb_in_Ocean.mp4 Huge_Chunk_of_Sodium_in_Pond.mp4 Brainiac_Alkali_Metals.mp4 Group_2_Reactions_with water_ _Periodic_Properties.mp4