Chemistry Chapter 8 - Periodic Table PDF

DARRELL ER (COPYRIGHTED) © DARRELL ER (COPYRIGHTED) © TOPIC 8: PERIODIC TABLE 1  DARRELL ER (COPYRIGHTED) © THE ABOUT Content heavy chapter 3...

DARRELL ER (COPYRIGHTED) © DARRELL ER (COPYRIGHTED) © TOPIC 8: PERIODIC TABLE 1  DARRELL ER (COPYRIGHTED) © THE ABOUT Content heavy chapter 3 key concepts TIME CHAPTER Usually tested along with ‘Atomic Structure’ & ANALYSIS EXAM ‘Chemical Bonding’ Highly tested on specifically ‘alkali metals’, ‘halogens’ & ‘noble gases’. Medium overall weightage Constitute to 4% of marks for past 5 year papers WEIGHTAGE 2  DARRELL ER (COPYRIGHTED) © KEY CONCEPT PERIODIC TABLE & TRANSITION METALS ALKALI METALS HALOGENS NOBLE GASES 3  DARRELL ER (COPYRIGHTED) © PERIODIC TABLE Trend across a period (left to right) - Number of protons increases - Atomic radius decreases - Metallic properties decreases Trends down a group (top to bottom) Horizontal rows are known as periods. (Represent number of electron shells.) - Number of protons increases - Number of electron shells increases Vertical rows are known as groups. (Represent number of valence - Atomic radius increases electrons.) - Metallic properties remain constant The block of elements between Group II and Group III are called transition metals and they tend to have variable oxidation states. 4  DARRELL ER (COPYRIGHTED) © ION FORMATION Metallic elements will form cations as they lose their PERIODIC TABLE valence electrons to form positively charged ions. For example, Group I elements like Sodium (Na) will form Na+ with charge +1. Group I II III IV V VI VII VIII Valence 1 2 3 4 5 6 7 8 electro ns Period Li Be B C N O F Ne II Ion Li+ Be2+ B3+ - N3- O2- F- - Non-metallic elements will form anions as they gain Period Na Mg Al Si P S Cl Ar electrons to form negatively charged ions. III For example, Group VII elements like chlorine (CI) will form CI - with charge of –1. Ion Na+ Mg2+ Al3+ - P3- S2- Cl- - 5  DARRELL ER (COPYRIGHTED) © TRANSITION METALS PHYSICAL PROPERTIES OF TRANSITION METALS Transition metals has high melting points and high densities due to the strong metallic bonds. They are good electrical and thermal conductors. Transition metals also form coloured compounds. CHEMICAL PROPERTIES OF TRANSITION METALS Transition metals has the ability to exhibit multiple oxidation states. Hence, they are frequently used as catalysts. For example, iron is used in the Haber process to produce TRANSITION METALS ammonia, and nickel is used in making margarine through the process of adding hydrogen to vegetable oil (hydrogenation). Transition metals are found in between the Group II and Group III elements in the periodic table. 6  DARRELL ER (COPYRIGHTED) © ALKALI METALS PHYSICAL PROPERTIES OF ALKALI METALS Name of element Melting points / °C Density / gcm-3 - Low melting points Lithium (Li) 180 0.534 - Low densities, lithium, sodium and potassium can float on water Sodium (Na) 98 0.971 - Good conductor of electricity & heat Potassium (K) 63 0.862 Rubidium (Rb) 39 1.532 Densities of alkali metals generally increase down the group while Caesium (Cs) 28 1.873 melting points decrease down the group. Francium (Fr) 27 - This is due to the increase in atomic radius down the group. (decreases down the (increases down the group) group) GROUP I: ALKALI METALS Chemical properties of alkali metals Group I elements are called alkali metals as they react with water to give As they have only one valence electron in their outermost shell, they alkaline solutions. form ionic compounds, with their resulting ions of +1 charge. Reactivity of alkali metals increases down the group due to the extra electron shells and the nucleus is further away, which increases Metal Chloride Nitrate Carbon Sulfate Oxide Hydroxid the ease of losing the valence electron. ate e Lithium LiCl LiNO3 Li2CO3 Li2SO4 Li2O LiOH Sodium NaCl NaNO3 Na2CO3 Na2SO4 Na2O NaOH Potassium KCl KNO3 K2CO3 K2SO4 K2O KOH 7  DARRELL ER (COPYRIGHTED) © HALOGENS PHYSICAL PROPERTIES OF HALOGENS - Low melting and boiling points that has an increasing trend down the group Name of element State Colour - Densities of the halogens increase down the group - Dissolve sparingly in water (chlorine, bromine and iodine) generally, but soluble in organic solvents. - Does not conduct electricity due to a lack of mobile charge carriers Fluorine (F2) Gas Pale Yellow Chlorine (Cl2) Gas Green Yellow Bromine (Br2) Liquid Reddish brown CHEMICAL PROPERTIES OF HALOGENS Iodine (I2) Solid Black Astatine (At2) Solid Black Reactivity decreases down the group. The ease of gaining a valence electron decreases as the valence shell is further away from (increases down (increasing colour intensity) the nucleus, making it more difficult to attract an electron. the group) DISPLACEMENT REACTION A more reactive halogen is able to displace a less reactive halogen GROUP VII: THE HALOGENS from an aqueous solution of its ions. Halogens usually exist as diatomic molecules. Cl2 (aq) + 2KBr (aq)  2KCl (aq) + Br2 (aq) The solution will turn reddish brown due to the aqueous bromine produced. 8  DARRELL ER (COPYRIGHTED) © NOBLE GAS PHYSICAL PROPERTIES OF NOBLE GASES Name of Melting points / °C Boiling points / °C State - Do not conduct electricity (lack of charge carriers) element - Very low melting and boiling points - Increasing melting and boiling points going down the group Helium (He) - -269 Gas - Increasing densities of noble gases going down the group Neon (Ne) -248 -246 Gas Argon (Ar) -189 -186 Gas USE OF NOBLE GASES Krypton (Kr) -157 -153 Gas Xenon (Xe) -111 -108 Gas Element Application Reason Radon (Rn) -71 -62 Gas (increases down the (increases down the Helium (He) Fill airships & hot air balloons Low density comparative group) group) to air GROUP 0: THE NOBLE GASES Neon (Ne) Fill interior of neon light tubes Unreactive gas All noble gases have a fully filled valence shell. Noble gases are unreactive and inert since they have a stable electronic configuration. Argon (Ar) Fill light bulbs Unreactive gas They exist as mono-atomic particles (single atoms). 9 Try it yourself! (TYS Question) Answer: Try it yourself! (TYS Question) Answer: About Us Notes prepared by: OVERMUGGED is a learning platform created by tutors, for students. Our team of specialist tutors offer 1-to-1 private tuition, group tuitions and crash courses. Follow us on IG and join our Telegram channel to get the latest updates on our free online revision sessions, webinars and giveaways! If you would want to join Darrell's group tuition, contact him at: Whatsapp: 8777 0921 Telegram: @DarrellEr Website: https://www.overmugged.com/darrell Darrell Er For more free notes & learning materials, visit: www.overmugged.com 'O' Levels Chemistry & Physics  OVERMUGGED's Curated Notes Lower Sec 'A' levels $30 $40 Found the free notes useful? We got something better! OVERMUGGED's curated notes is a highly condensed booklet that covers all content within the MOE syllabus. This booklet consist of key concept breakdowns, worked examples and exam tips/ techniques to required to ace your exams. Get an upgraded version of the free notes and supercharge your revision! Purchase here. 'O' levels $40/$50 Crash courses Check out our upcoming crash courses at: https://www.overmugged.com/crashcourses 'O' levels subject available: - Pure Chemistry - Pure Physics - Pure Biology - Combined Science - E-Math -A-Math -English - History - Geography - Combined Humanities - Principles of Accounts (POA)