Metals and Non Metals

Metals Good conductors of heat and electricity. They are all solids at room temperature except mercury. Most of them can be hammered into different shapes (malleable) and drawn into wires (ductile). Metals have a shiny appearance.

Group 1 Alkali Metals soft metals cut with a knife to give a shiny surface. have low density – Li, Na, K float on water. very reactive metals & stored under paraffin oil. reactivity increases down the group. alkali metals react vigorously with water to give hydroxides and hydrogen.

Group 1 Alkali Metals Lithium is used in batteries since they are powerful and lightweight Sodium is used in street lamps and nuclear reactors Potassium is essential for the healthy growth of plants

Group 2 Alkaline Earth Metals harder metals. have higher density compared to Group 1. less reactive than Group 1. reactivity increases down the group. they react with oxygen when heated to give the oxides.

Group 2 Alkaline Earth Metals Magnesium is used in rescue flares and fireworks. Calcium carbonate is present in limestone, marble or chalk. Barium sulphate which is insoluble is used in barium meals. A patient takes it so that their digestive system will show up on X-ray.

Transition Metals less reactive than Group 1 and 2. hard and dense. good conductors of heat and electricity. High mpts, bpts (very strong metallic bond) have coloured ions except for zinc.

Non Metals Poor conductors of electricity and heat. Usually have low melting points (11 of them are gases and 1 is a liquid at room temperature). Brittle Dull appearance.

Group 7 Halogens low mpts & bpts. fluorine is a pale yellow green gas chlorine is a greenish- yellow gas bromine is dark red orange liquid iodine is dark grey crystalline solid.

Group 7 Halogens Fluorine is the most reactive of all non-metals Teflon is a fluorine compound used in non-stick lining on pans Most toothpaste contain fluoride to prevent tooth decay

Group 7 Halogens Chlorine: kills bacteria in swimming pools Bromine is used in pesticides and to make medicine. Iodine is an antiseptic.

Group O Noble gases colourless gases. exists as separate atoms. found in the Earth’s atmosphere. have low mpts and bpts .

Page 64 Metals Non Metals Appearance Shiny Dull State at r. t. Solids except Hg Solids/liquids/gases Conductivity Good conductors Poor conductors Strength Strong Weak Density High Low Melting point

Group O Noble gases Helium is used in air ships. Argon is used in light bulbs. It won’t react with the tungsten filament. Neon glows red in low pressure tubes when high voltage is applied. Krypton is used in lasers to repair the retina behind the eye.

Isotopes Look at the following chlorine atoms 3517Cl 3717Cl What is the difference between them?

Isotopes 3517Cl 3717Cl Electrons 17 17 Protons 17 17 Neutrons 35 – 17 = 18 37 – 17 = 20

Isotopes Therefore, isotopes are atoms of the same element with the same number of protons but different number of neutrons

Page 65 Isotope Protons Neutrons Electrons 126 C 146 C 6 6 6 6 8 6

Page 66 Isotope Protons Neutrons Electrons 3517Cl 17 18 3717Cl 20 7935Br 35 44 8135Br 46 168O 8 188O 10 126C 6 136C 7 146C

Page 66 Isotope Protons Neutrons Electrons 2612Mg 12 14 2512Mg 13 11H 1 21H 31H 2

Class work Page 68 Carbon atom Hydrogen atom carbon hydrogen Number of protons 6 1 Number of neutrons Number of electrons Electronic configuration 2,4

Class work Sodium atom Fluorine atom F Na Sodium Fluorine Number of protons 11 9 Number of neutrons 12 10 Number of electrons Electronic configuration 2,8,1 2,7

Question 6 The statements below are about metals and non-metals. Circle which is true or false All metals conduct electricity. True All metals are solid at room temperature. False Non-metals are good conductors of electricity. False Non-metals are solids, liquids or gases at room temperature. True Most metals are brittle and break when hammered. False Most metals are ductile. True There are many more metals than non-metals in the periodic table True

Question 7 The element Boron exists as 2 different isotopes. 10 5B 11 5B Natural Boron contains about: 20% Boron – 10 and 80% Boron – 11 What are isotopes? Atoms of the same element having same number of protons but different number of neutrons. Using the two isotopes of Boron as an example explain how the atoms are different from each other. Boron-10 has 5 protons and electrons and neutrons, Boron-11 has 5 protons and electrons but 6 neutrons.

Page 70 question 8 1 2 3 4 5 6 7 1 2 3 4 5 6

Property Name of element the lightest element Hydrogen a noble gas which is found in tungsten bulbs Argon the element with proton number 5 boron the element with 6 electrons in its atoms Carbon an element with 6 outer shell electrons and is a yellow solid sulphur the most reactive alkali metal Caesium the least reactive alkali metal Lithium

the most reactive halogen Fluorine a group 3 metal which is used in cans Aluminium an alkaline earth metal which is used in distress flares Magnesium a red-brown transition metal Copper a Group 5 non-metal which is found in the atmosphere Nitrogen a metal that is magnetic Iron a colourless gas used to fill weather balloons and airships Helium a metal that is so reactive it has to be stored under oil Potassium a greenish yellow poisonous gas. Chlorine