Intermediate 1 Chemistry S3 Revision

Atoms and Elements

Elements If a solid, liquid or gas is made up of only one type of atom we say it is an element. For example, consider a tripod made up of iron: These atoms are ALL iron – there’s nothing else in here

The structure of the atom ELECTRON – negative, mass nearly nothing PROTON – positive, same mass as neutron (“1”) NEUTRON – neutral, same mass as proton (“1”) The Ancient Greeks used to believe that everything was made up of very small particles. I did some experiments in 1808 that proved this and called these particles ATOMS: Dalton

Atoms and charges #1 Protons have a __________ charge Electrons have a ___________ charge Neutrons don’t have a charge So if an atom contains charged particles then why is the total charge on an atom always zero???????????

Atoms and Atomic number The atomic number of an element always tells us the number of _________ in the nucleus of each atom. We can find the atomic number on most _________ _________. As we go across a row from left to right the atomic number goes up by ______.

Atoms and Atomic number #2 The atomic number for lithium is _____ The atomic number for carbon is _____ The atomic number for iodine is _____ The atomic number for copper is _____ A boron atom has ____ protons in its nucleus. A calcium atom has ____ protons in its nucleus. A gallium atom has ____ protons in its nucleus. The atomic number for tin is _____ A uranium atom has ____ protons in its nucleus. An oxygen atom has ____ protons in its nucleus.

Mendeleev Periodic table The periodic table arranges all the elements in groups according to their properties. Horizontal rows are called PERIODS Vertical columns are called GROUPS

H HeHe Li BeBe BCNOF NeNe NaNa MgMg AlSiPSClAr K CaCa FeNi CuCu ZnBrKr AgAg IXe Pt AuAu HgHg The Periodic Table Fact 3: Most of the elements are metals: These elements are metals This line divides metals from non- metals These elements are non-metals

H HeHe Li BeBe BCNOF NeNe NaNa MgMg AlSiPSClAr K CaCa FeNi CuCu ZnBrKr AgAg IXe Pt AuAu HgHg The Periodic Table Fact 4: (Most important) All of the elements in the same group have similar PROPERTIES. E.g. consider the group 1 metals. They all: 1)Are soft 2)Can be easily cut with a knife 3)React with water

Group 1 – The alkali metals Li Na K Rb Cs Fr

Group 0 (or 8) – The Noble gases He Ne Ar Kr Xe Rn

Group 0 – The Noble gases Some facts… 1) All of the noble gases have a full outer shell, so they are very _____________ 2) They all have low melting and boiling points 3) Helium is lighter then air and is used in balloons and airships (as well as for talking in a silly voice) 4) Argon is used in light bulbs (because it is so unreactive) and argon, krypton and neon are used in fancy lights

Group 7 – The halogens F Cl Br I At

Compounds

Compounds are different to elements. They contain different types of atoms joined together. Here are some examples: Glucose Methane Sodium chloride (salt)

Some simple compounds… Methane, CH 4 Water, H 2 O Carbon dioxide, CO 2 Ethyne, C 2 H 2 Sulphuric acid, H 2 SO 4 Key Hydrogen Oxygen Carbon Sulphur

Covalent Compounds Covalent bonds only appear in non-metal compounds like water (H 2 O) and Carbon dioxide(CO 2 ) The compounds are also known as molecules and the covalent bonds are very strong between the non-metal atoms. Between all the molecules there is weak forces holding them together.

Covalent Compounds Covalent Water Molecules (H 2 O) HH O HH O HH O atom Strong covalent bond weak bond

Ions in Compounds Ions are charged particles which are contained in ionic compounds. Ions can be either positively charged (+) or negatively charged (-) Ions are attracted to each other and form very strong bonds.

Ions in compounds Ionic Compound ions Strong bonds

Naming compounds Fill in the blanks below using the table on the previous slide to help you. Copper and chlorine will make ________ _________ Iron and sulphur will make ________ _________ Magnesium and oxygen will make ________ _________ Calcium and fluorine will make ________ _________ _________ and ________ will make barium nitride

Naming compounds Fill in the blanks below using the previous slide to help you. Copper, carbon and oxygen will make ________ _________ Lithium, sulphur and oxygen will make ________ _________ Calcium, nitrogen and oxygen will make _______ _________ Potassium, carbon and oxygen will make _______ ________ _______, _______ and _______ will make silver nitrate

Mixtures 100 g 105 g Before After

Element, mixture or compound? Salty waterHydrogen Hydrochloric acid Sodium chloride (salt) Diamond Air

Elements, compounds or mixture Decide whether each of the samples is an element, mixture or compound. Salt water = _____________ Hydrogen = _____________ Hydrochloric acid = _____________ Air = _____________ Diamond = _____________ Salt = _____________

Solutions and separating

Dissolving things – some meanings If a substance CAN be dissolved it is __________ If a substance CANNOT be dissolved it is _________ Words – soluble, solute, solvent, solution, insoluble

Distillation - separating liquids Distillation can be used to separate water and ethanol because they have different _______ ______. The ______ will boil first, then turn back into a _______ in the condenser and collect in the _______. The water will stay in the round flask, as long as the _______ does not go above ______ O C. Words – 100, temperature, oil, boiling points, ethanol, beaker, liquid Distillation is used to separate crude _______ into useful fuels like petrol.

Separating mixtures summary 1)A mixture containing a solid and a liquid can be separated using __________ 2)A mixture of liquids with different boiling points can be separated using _________ 3)A mixture of different inks can be separated using _______ 4)Water can be removed from a solution by ___________ 5)Separation methods are _____ chemical reactions because a _____ substance is not being made. Distillation, not, chromatography, new, evaporation or filtration

Saturated solutions Consider our previous work on solutions: Clearly, there is only so much solute a solution can take… A mixture that cannot take any more solute is called a “saturated solution”

Solubility words Solute Solution Solvent Soluble Insoluble Saturated Solubility Something that CAN dissolve is described as being… How much of something that can be dissolved is called… Something that CANNOT be dissolved is described as being… A solution that CAN’T dissolve anything else is… The solid that will be dissolved is the… The mixture of solute and solvent is called the… The liquid that the solute will be dissolved into is the… Draw lines to match up the words to their meanings. One has already been done for you.

Chemical Reactions

Testing for oxygen Oxygen will make a glowing splint _______

Testing for hydrogen “POP” Hydrogen makes a ___________ splint go _______.

Testing for carbon dioxide Carbon dixoide makes ___________ go __________ Carbon dioxide Gas Limewater

Adding acids to metals Words – gold, hydrogen, bubble, copper, used up Some metals react with acids to produce ________ gas. The gas will make the mixture _______ and the metal will eventually be _______ _____. Some metals, like _______ and _______, are so unreactive that nothing will happen.

Adding acid to carbonates Carbonates are compounds that react with acids to make _________ __________ gas. This makes the mixture _________. When all of the carbonate is used up the _________ will stop. Carbonates used to be used as building materials but aren’t any more because acid rain would eventually ________ the building. Words – dissolve, bubble, carbon dioxide, bubbles Limewater goes cloudy

Acids and Alkalis Name_____________________

Universal Indicator and the pH scale Below 7 is _____ Above 7 is _________ Exactly 7 is _________ Universal Indicator changes colour depending on whether it is in an acid, alkali or neutral solution. Stomach acidLemon juiceWaterSoapOven cleanerBaking powder

Quiz on acids and alkalis 1)This has pH of less than 7 ____________ 2)This is often used in cleaners or soap __________ 3)This would turn Universal Indicator red ________ 4)Sodium hydroxide is an ____________ 5)This would feel soapy on your skin _________ 6)This could burn your skin _________ 7)This will turn universal indicator purple _________ 8)Lemon juice and vinegar are examples of weak _______ 9)limewater (calcium hydroxide) is an example of this__________ Acid, alkali or both???

E.g. hydrochloric acid + sodium hydroxidesodium chloride + water Neutralisation An acid and alkali will cancel each other out (neutralise) each other if the correct amounts are used Acid + alkaliSalt + water This reaction is called ________________ because the acid is used up and _________ is made. Choose your answers from the list below: combustionrespirationneutralisation hydrogenwateroxygen

Adding potassium hydroxide to sulphuric acid will make water and a salt called _________ _________. Complete the blank spaces Adding sodium hydroxide to hydrochloric acid will make water and a salt called sodium _________. Adding sodium hydroxide to nitric acid will make water and a salt called sodium _________. Adding magnesium hydroxide to hydrochloric acid will make water and a salt called _________ _________. Adding lithium hydroxide to sulphuric acid will make water and a salt called _________ _________.

Adding acid to carbonates Carbonates are compounds containing carbon and oxygen. When an acid and a carbonate are added together, the mixture starts to fizz. A gas called _________ _________ is produced. The limewater will go __________

Adding potassium carbonate to sulphuric acid will make carbon dioxide, water and a salt called ___________ _________. Complete the blanks spaces Adding sodium carbonate to hydrochloric acid will make carbon dioxide, water and a salt called _________ _________. Adding sodium carbonate to nitric acid will make carbon dioxide, water and a salt called __________ _________. Adding magnesium carbonate to hydrochloric acid will make carbon dioxide, water and a salt called ___________ _________. Adding copper carbonate to sulphuric acid will make carbon dioxide, water and a salt called _________ _________.

Reactions of metals with acids When a metal reacts with an acid a gas called ______________ is made. A salt is also made at the same time. METAL + ACID SALT + ____________ e.g. magnesium + hydrochloric acid magnesium chloride + hydrogen The name of the salt depends on the metal and the acid. Complete the following reactions: Calcium + hydrochloric acid _________ ________ + __________ Zinc + hydrochloric acid _________ ________ + __________ Iron + nitric acid _________ ________ + __________ Lithium + sulphuric acid _________ ________ + __________ These reactions are not neutralisation because _________ is not being made.

Useful acid-alkali reactions 1) Hydrochloric acid is used in the stomach to help digest food. If we eat too many “rich” foods our stomachs make too much ______. This is called _____________. Indigestion tablets take away this pain because they ______________ the acid. 2) Soil is often acidic, mainly due to acid ____. This can have bad effects on ______ and vegetable growth. ________ is an alkali that farmers and gardners add to soil to _________ the acid. Words – plant, indigestion, neutralise, rain, acid, neutralise, lime

Uses of acid reactions When acids react new chemicals called salts are made. These salts have many uses. Sodium chloride is the chemical name for table salt that we put on our chips. Salts that are made from nitric acid contain nitrate. Nitrates are needed by plants to help them grow. Chemical companies use nitric acid to make nitrate salts for farmers to use as fertilisers for their crops. Nitrate salts are also used in explosives.

Acid gases The names of three acid gases are:  _________ _________ When fossil fuels like coal, _____ or natural _____ are burned in power stations, the carbon contained in them reacts with oxygen to form ___________ dioxide gas. Carbon dioxide also comes out of car exhausts. Some fossil fuels contain sulphur. When the fuel burns, the acid gas called _________dioxide is made. A car engine needs a spark to set the petrol on fire. The energy from the spark makes nitrogen and oxygen join together to make the acid gas called__________ dioxide gas.

Problems with acid gases The acid gases called _________ dioxide, _________ dioxide and _______ dioxide dissolve in cloud droplets and fall as _____ ______. The acid rain gets into rivers and streams and kills ______. It can kill ______ when it falls onto their leaves. Acid rain can also damage stone buildings and metal structures because it reacts and eats them away.

The reactivity series of metals

Metals with oxygen When a metal is heated with oxygen it will glow and turn into a METAL OXIDE.. The colour and brightness of the glow can tell us about how reactive the metal is. The order of reactivity most to least is ____________ then ____________ then ____________.

Order of reactivity To work out which metals were more reactive than others the number of bubbles made in one minute were counted. Tin made 10 bubbles in one minute Zinc made 17 bubbles in one minute Copper made 0 bubbles in one minute Calcium made 34 bubbles in one minute Magnesium made 28 bubbles in one minute Aluminium made 23 bubbles in one minute Iron made 13 bubbles in one minute

Reactivity series so far A reactivity series of a list of metals in order of how _________ they are. The ________ reactive metal goes at the top of the list. lithium magnesium copper iron calcium tin sodium aluminium potassium zinc Put these metals in order of reactivity: ____________ Most reactive Least reactive

Reactions of Metals METAL + OXYGEN METAL OXIDEMETAL + WATERMETAL HYDROXIDE + HYDROGENMETAL + ACID SALT + HYDROGEN e.g. magnesium + hydrochloric acid magnesium chloride + hydrogen eg calcium + watercalcium hydroxide + hydrogen eg magnesium + oxygenmagnesium oxide You need to know 3 reactions of metals:

Complete the following reactions: 1)Lithium + water 2)Lithium + hydrochloric acid 3)Silver + oxygen 4)tin + hydrochloric acid 5)Potassium + oxygen 6)Aluminium + oxygen 7)Magnesium + water 8)zinc + hydrochloric acid 9)Lithium + oxygen 10)calcium + hydrochloric acid _______ _______ + _________ _______ _______ _______ + _________ _______ _______ _______ + _________ _______ _______ _______ + _________