7 Chemical Properties of metals and nonmetals.pptx

Chemical Properties of metals and nonmetals Physical Vs. Chemical properties what is the difference between physical and chemical properties https://www.youtube.com/watch?v=x49 BtB5dOwg&t=200s Physical Vs. Chemical properties A physical property is a char...

Chemical Properties of metals and nonmetals Physical Vs. Chemical properties what is the difference between physical and chemical properties https://www.youtube.com/watch?v=x49 BtB5dOwg&t=200s Physical Vs. Chemical properties A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. A chemical property is a characteristic of a particular substance that can be observed in a chemical reaction. Chemical reaction A process in which one or more substances, the reactants, are converted to one or more different substances, the products. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.​ It is to study how chemicals react. Chemical reaction Kahoot Time  https://create.kahoot.it/details/physical-and-chemical-ch ange-and-properties/5d735c6c-03f5-4cc0-81d9-af02706 4da8e Chemical reactivity The reactivity of elements depends on the number of valence electrons. If the outer shell of an atom contains 8 valence electrons, this means the atom is stable and it’s unreactive (noble gases) If the outer shell has less than 8 valence electrons, then the atom is unstable and reactive Reactivity is how likely an atom is to react with other substances Reactivity of group I metals It is their tendency to lose one valence electron to have the electronic configuration of a noble gas and become stable Na: 2,8,1 → tendency to lose one electron → it becomes a positive ion of charge +1 → Na+: 2,8 Read workbook 2 (pages 43-46) Reactivity of group 1 with water All the alkali metals react vigorously with water. In each reaction, hydrogen gas is given off and the metal hydroxide is produced. The speed and violence of the reaction increases as you go down the group. https://www.youtube.com/watch?v=dUAmscn6OCg Brainiac Alkali Metals - YouTube Kahoot Time  https://create.kahoot.it/details/alkali-metals/4b95dfef-e6 8b-4081-becd-9d0d2a3d27f9 Reactivity of group II metals It is their tendency to lose two valence electron to have the electronic configuration of a noble gas and become stable Mg: 2,8,2 → tendency to lose 2 electrons →it becomes a positive ion of charge +2 → Mg2+: 2,8 Workbook 2/page 47 Explain how the reactivity of group II metals change down the group Moving down group (2), reactivity increases because the radius of the atom increases due to the increase in the number of shells, so the valence electron become far away from the nucleus causing the force of attraction between them to get weaker, thus it gets easier and faster to lose the two valence electrons. Workbook 2/page 48 Group II metals are less reactive than group I. Suggest an explanation Group 2 metals have the tendency to lose 2 electrons while in group 1 metals have the tendency to lose 1 electron to obtain a full outer shell Losing 1 electron is easier than losing 2 electrons even if they are in the same energy level Transition elements Common Physical and chemical properties: They form colored compounds They are good conductors of heat and electricity They can be hammered or bent into shape easily They are less reactive than alkali metals such as sodium. Transition metals react with oxygen to form metal oxides. However, gold, silver, and platinum do not react with oxygen. They have high melting points - but mercury is a liquid at room temperature They are usually hard and tough They have high densities Workbook 2/pages 49-50 Question? Compare and contrast the chemical properties of Sodium and Iron. Similarities Differences Both react with water and Na is more reactive than Fe oxygen Both of them can form an ion Fe forms a colored compound Na forms a colorless or white compound  Halogens The outer shell of halogens has 7 valence electrons and so they have tendency to gain one electron and turn to negative ions of charge -1 to have the electronic configuration of a noble gas and become stable Workbook 2/page 51 Interpret the above diagram to suggest how reactivity of halogens change down their group Moving down group 17, the reactivity decreases because the radius of the atom increases and the new coming electron becomes further away from positive nucleus and less attracted, so the tendency to gain electrons becomes more difficult and reactivity decreases down the group of halogen. Reactivity of metals: Reactivity of non-metals: Attraction to nucleus, Workbook 2/ page 53 Q1 Apply the theories of reactivities that you learned to predict which of the two elements X or Y is more reactive: [Give reasoning] Note: you are given their electronic configurations a) X: 2,8,18,5 Y: 2,8,18,18,5 X is more reactive than Y, both have the tendency to gain 3 electrons to obtain a full outer shell and become stable, however the valence electron in X is in the 4th shell while in Y in the 5th shell so the distance between the valence electrons and the nucleus in X is less. Making the attraction forces between them stronger and easier to gain 3 electrons  Workbook 2/ page 53 b) X:2,8,18,8,2 Y:2,8.18.8,1 Y is more reactive than X Both have 5 energy shell, however Y has the tendency to lose 1 electron while X has the tendency to lose 2 electrons to obtain a full outer shell and become stable Losing 1 electron in Y is easier than losing 2 electrons in X Workbook 2/ page 54 Q2 Analyze the following data to suggest the state and group of the unknown elements A,B,C.D and E Element Melting point Boiling point Density o C o C g/cm3 A -270 -269 0.00017 B 180 1360 0.53 C 840 1490 1.53 D -7 59 3.12 E 1540 2760 7.87 A: Gaseous state, Noble gases B: Solid state, Group 1 C: Solid state, Group 2 D: Liquid state , Transition metal (mercury) E: Solid state, Transition metal Workbook 2/ page 54 Q3 Compare the physical properties of a) Potassium and calcium Workbook 2/ page 55 b). Iron and chlorine Workbook 2/ page 55 Q4 Distinguish the physical properties of elements A and B given that the atomic number of A is 10 and that of B is 12 A :2,8 (noble gas) B :2,8,2 (Alkaline earth metal) 1. A has lower density than B 2. A is colorless while B is silver-gray Workbook 2/ page 56 Q5 Outline Why a magnesium ion has a constant charge +2 Mg atom has the tendency to lose 2 valence electrons to obtain a full outer shell and become stable. Q6 outline why noble gases do not form ions Because noble gases have a full outer shell so they don’t have the tendency to lose or gain electrons Workbook 2/ page 56 Q7 Describe the trend in reactivity of group 16 Elements in group 16 have the tendency to gain 2 electrons to obtain a full outer shell and become stable. Moving down the group, the reactivity will decrease because the radius of the atom gets bigger due to the increase in the number of shells so the valence electrons become far away from the nucleus and force of attraction between them get weaker, making the gain of electrons harder and slower.