Do Now 1/12/10 Explain IN COMPLETE SENTENCES why atoms are neutral in charge. HINT: think about the charges and numbers of the subatomic particles Reminder: Bring your binders and books tomorrow! Also Dodgeball this Thursday, only $3, teachers vs Students Take out a sheet of paper, setup cornell notes, titled, Ions Do Now Discussion Atoms are neutral because they have equal numbers of protons and electrons. Protons are positively charged and electrons are negatively charged When equal in number, the charges cancel each other out. Review: What is an ion? A single atom or groups of atoms with either a positive or negative charge. Cation: positively charged ion Remember: Cats purrrrr. Anion: negatively charged ion Think: If you are anti something, you are against it, or have a negative opinion of it. How do Ions form? Ions form when atoms lose or gain valence electrons. Lose electrons = Make a CATION Gain electrons = Make an ANION NaNa + Atoms want 8 e- in their valence shell so it is full. This will give them the configuration of a noble gas Atoms lose, gain, or share e- in order to get 8 e- in their valence shell NaCl+Na + Cl+ - Cation, Like Ne Anion, Like Ar Octet Rule octo means 8 Trends in Ion Formation Groups 1, 2, 13 & sometimes 14 give their valence electrons away (lose) LiLi + MgMg 2+ B B 3+ Trends in Ion Formation Groups 15, 16, 17 take electrons (gain) P P 3- O O 2- F F - Trends in Ion Formation Group 18 doesnt form ions (noble gases) They already have the lucky 8 electrons! 18 Exit Slip 5 pts Complete the next 3 examples on your own, turn in to Mr. Sandine on your way out Use a half sheet of paper Correct your answers as we go for full credit Example 1 What would be the ion for Calcium (Ca)? Group Gain/Lose electrons Charge 2 Lose 2+ Ion Ca 2+ Example 2 What would be the ion for Boron (B)? Group Gain/Lose electrons Charge 13 Lose 3+ Ion B 3+ Example 3 What would be the ion for Phosphorus (P)? Group Gain/Lose electrons Charge 15 Gain 3- Ion P 3- Do Now 1/13/10 What would be the ion for Sulfur (S)? Group Gain/Lose electrons Charge 16 Gain 2- Ion S 2- One more What would be the ion for Beryllium (Be)? Group Gain/Lose electrons Charge 2 Lose 2+ Ion Be 2+ Practice What group is Sodium in? What is the atomic #? How many: Protons = ______ Electrons = ______ What is the e- configuration for Na? How many valence e- does Na have? Group 1 1 from the 3s block = 1 valence e- 1s22s22p63s11s22s22p63s1 11 Na 11 protons 11 neutrons Na needs to loose 1 e- to have a full outer shell! Cation Practice What group is Fluorine in? What is the atomic #? How many: Protons = ______ Electrons = ______ What is the e- configuration for F? How many valence e- does F have? Group 17 2 from the 2s block + 5 from the 2p block = 7 valence e- 1s22s22p51s22s22p F 9 protons 9 neutrons F needs 1 more e- to fill its outer shell! Anion So what happens? F 9 protons 9 neutrons Na 11 protons 11 neutrons Na looses its single e- in the 3 rd energy level, donating it to F Na+ no longer has e- in the 3 rd energy level, but does have a full 2 nd energy level w/ 8 e- Has become a Na+ ion. F now has a full 2 nd energy level with a full 8 e-, and has become the F- ion. + - Complete 1-15 on the in class worksheet by the end of the period. Isotopes BrainPop! Ions are formed when an atom gains or looses: protons neutrons e- Isotopes are formed when an atom looses: protons neutrons e- What is formed when an atom looses a proton? A different element! Remember: The atomic # is determined by the # of protons in an atoms nucleus! Isotopes cont. Naturally occur, some more common than others The atomic mass of an element is determined by looking at the abundance of these different isotopes and calculating the average. THIS is why the atomic mass for the elements is not a whole #!! Atomic # on bottom Mass # Trends: Atomic Radius An atoms size is determined by the space occupied by its e- cloud Remember: The e- cloud is the area around the nucleus where the orbitals containing the e- are. Size is measured by determining the size of the radius. Turn to p. 187, look at graphic Radius of: Metals = the distance between nucleus of 2 atoms next to each other in crystal form Nonmetals = Distance between nuclei of 2 bonded atoms of the same element. Three Classes of Elements: Metals- Loose e- easily! Good conductors high luster or sheen Solid at room temperature (except Mercury) Ductile- drawn into wire Malleable- Able to bend, hammered into thin sheets without breaking Three Classes of Elements: Nonmetals- Poor conductors (Carbon is exception) Most are gases at room temperature Properties opposite of metals. Non-malleable Non-ductile Brittle (break easily) Three Classes of Elements: Metalloids- Properties similar to both metals and nonmetals Depends on the conditions Temperature Pressure Found where the metals and nonmetals meet on the periodic table.