Presentation on theme: "Day 4 – Reactivity & Ions Sci 10 Chemistry. Noble gases are the most popular group A full valence shell contains happy electrons that want to stay where."— Presentation transcript:
Noble gases are the most popular group A full valence shell contains happy electrons that want to stay where they are and are not very reactive (like the noble gases) The octet rule: atomes react in order to have a full valence (outer) shell
Group 1- Alkaline Metals The most reactive metals Group 2- Alkaline Earth Metals Reactive but not as reactive as Group 1 Group 7 - Halogens The most reactive non-metals Groupe 8 – Noble Gases Very unreactive. Stable because their valence shell is full
All atoms want to fill their valence shell To be stable and happy To be stable and happy i.e. How can Na fill its valence shell? Think of its Bohr-Rutherford diagram It can either: add 7 electrons (and be like Ar) OR lose 1 electron (and be like Ne) Which is easier???
Na cont’d It will lose its only valence electron The shell will no longer exist without an electron in it Na will now have 10 electrons on 2 shells (like Ne)
All atoms want to fill their valence shell i.e. How can F fill its valence shell? Think of its Bohr-Rutherford diagram It can gain an electron to be like Ne OR it can lose 7 electrons to be like He
F cont’d It will gain an electron to fill/ complete its valence shell F will now have 10 e- (like Ne)
Ions Ion: Atom or group of atoms that carries an electric charge Cation – Positively-charged ion formed when a neutral atom loses one or more electrons in order to have a filled valence shell Ex : energy + Na Na+ + electron 11 protons 11 protons 11 protons 11 protons -11 electrons - 10 electrons -11 electrons - 10 electrons 0 charge 1+ charge 0 charge 1+ charge **Remember: ditching something negative makes you more positive!
Which groups form cations? Group 1- Alkaline Metals Lose 1 e- (to have a full valence shell) so they form cations with a charge of 1+. i.e. : Na + Group 2 – Alkaline Earth Metals Lose 2 e- so they form cations with a charge of 2+ i.e.: Ca 2+ Almost all metals form cations
Ions Anion – Negatively-charged ion formed when a neutral atom gains one or more electrons in order to fill its valence shell Ex : F + electron F- + energy 9 protons 9 protons 9 protons 9 protons -9 electrons - 10 electrons -9 electrons - 10 electrons 0 charge 1- charge 0 charge 1- charge *Remember: getting more of something that is negative makes you more negative!
Which groups form anions? All non-metals Group 7 - Halogens gain 1 e- (to have a filled valence shell) so they form anions with a charge of 1- i.e. : Cl + e- Cl - + energy Group 6 gain 2 e- so they form anions with a charge of 2- i.e. : O 2–
Don’t forget… Cations are positive: the “t” looks like the symbol “+” Or: Cats have paws, cations are pawsitive Or: Cats have paws, cations are pawsitive Anions are negative
Naming Ions Anion - (nonmetal) name ends in "ide" i.e. Chlorine atom forms a chloride ion Cation - (metal) name is the regular name of the metal (no changes) i.e. Sodium atom forms a sodium ion
To do: Day 4 Ions & Atoms Practice Text p.109 #4, 9 Extra practice: Website – Keeping an Ion That Electron