#### Area & Volume Exploration &#150; Component proportional changes

Area & Volume Exploration - Component proportional changes Question 1: How do the Volume, Surface Area and Mass of your component vary when two key dimensions are changed but the length remains the same? Changing one key Dimension by 5%, 10% & 20% Increasing the length: 20m 5% increase => 20 ? 5% = 1 100 => 20m + 1m (increase) = 21m So... New cuboid dimensions = Length = 21m Width = 10m Height = 5m Volume = 10m ? 21m ? 5m = 1050m3 S. Area = (2?10?5)+(2?21?5)+(2?10?21) = 100 + 210 + 420 = 730m3 Mass = 7800kg/m3 ? 1050m3 = 8'190'000kg This clearly shows that when the length is increased by 5% the Volume and Mass are also increased by 5%. This indicates that the Volume and Mass are directly proportional to the length. The Surface Area would not appear to be directly proportional to the length as it does not increase by 5%. Further exploration is needed to confirm that this proportional increase is not a one off event. I predict that the same will happen and the percentage increase will be the same for Length, Volume and Mass. 10% increase => 20 ? 10% = 2 100 => 20m + 2m (increase) = 22m So... New cuboids dimensions = Length = 22m Width = 10m Height = 5m Volume = 10m ? 22m ? 5m = 1100m3 S. Area = (2?10?5)+(2?22?5)+(2?10?22) = 100 + 220 + 440 = 760m3 Mass = 7800kg/m3 ? 1100m3 = 8'580'000kg Volume = 10m ? 27m ? 5m = 1350m3

• Word count: 908
• Level: GCSE
• Subject: Science

#### History of Chemistry and Atomic Structure.

History of Chemistry and Atomic Structure Greeks - First to consider the nature of matter (400 BC) ) Two camps: a) matter is continuous - keep on dividing matter indefinitely; you just get smaller pieces Aristotle believed that matter was continuous b) matter is finite; it is composed of small indivisible particles Democritus - everything made up of atoms (atoms - Greek for "indivisible") 2) 4 different types of "elements" or "atoms" : Fire, Earth, Water, Air How were these 4 types of "atoms" different - they were especially interested in shape since Greeks were really into geometry: Fire - jagged shaped, since fire hurt Water - spherical, smooth since water flowed easily Earth - cubical - earth was solid and stable 3) The Greeks were not doing science as we know today but an intellectual exercise (philosophy) since no evidence existed one way or the other and they had no experiments to test their ideas (science) 4) Aristotle held more prestige and his ideas about matter held on for almost 2000 years. Alchemists ( 0 - 1500AD) Based upon the idea that there were only 4 different types of matter, the variety all around them lead scientists to believe that each different substance (say lead and gold) must be made up of different proportions of the 4 "elements". If one could separate the 2 elements and recombine them in different proportions, one could

• Word count: 1192
• Level: GCSE
• Subject: Science

#### The differences between the Alkali metals and the Transition metals.

`The differences between the Alkali metals and the Transition metals In this essay I will explain the differences between the alkaline metals of Group 1 (la) in the periodic table and the Transition elements of groups 3 to 12 (lllb - llb) I will explain the reactivity, density, melting point, electronic metals and the uses. I will also compare the differences between the two groups. What are the Alkali metals? The alkali metals are a group of six elements that are in-group 1 of the periodic table. They have low melting points are soft compared to other metals and are so reactive that they are always combined with other elements. They are powerful reducing agents this meaning that they are always willing to lose an atom to have a complete outer shell that makes the element stable. What are the Transition elements? These elements are elements that share the same electronic orbital structure; this means that they have similar chemical properties. These elements are defined as 31 elements that have atomic numbers that range from 21-30, 39-48 and 71-80 in the periodic table .The transition metals sometimes take on negative oxidation states. There properties are similar to other metals: there similarities include malleability, ductility, high conductivity of heat and a high conductivity of electricity. The elements act as reducing elements or otherwise "Donors of electrons"

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• Word count: 1302
• Level: GCSE
• Subject: Science

#### To demonstrate the principle of osmosis, the diffusion of water through a semi permeable membrane.

Osmosis in Plant Cells Aim- to demonstrate the principle of osmosis, the diffusion of water through a semi permeable membrane. Apparatus: * 3 carrot slices * 3 raisins * 6 small labels * 6 thin plastic containers * 2x25 ml of distilled water (0 M ) * 2x25 ml of salty water ( 0.5 M ) * 2x25 ml of salt water ( 1 M ) * measuring cylinder * Balance Diagram: Method: ) Distilled, salty, and salt water was measured using a measuring cylinder, and placed into 6 plastic containers. 2) The containers were labeled, and distributed in three pairs. 3) Each individual carrot/raisin was weighed. 4) The apparatus was then set as shown on the diagram. 5) The carrots and raisins were left over 40/45 minutes. 6) Each individual carrot/raisin was weighted once again. 7) Results were recorded and observations taken down. Results: Carrots Salt Concentration (M) Mass of carrot before (g) Mass of carrot after (g) 0 M 3.34 g 2.24 g 0.5 M 3,47g 2.55 g M 3,67 g 3.67 g Observations after % change in Mass Difference in Mass (g) smoother appearance, lighter 32.9 % .1 g quite crumpled 26.5% 0.92 g quite crumpled, nearly equal 0% 0 g Raisins Salt Concentration (M) Mass of raisin before (g) Mass of raisin after (g) 0 M 0.24 g 0.37 g 0.5 M 0.37 g 0.40 g M 0.19 g 0.20 g Observations after % change in Mass Difference in Mass (g) Sobby,

• Word count: 570
• Level: GCSE
• Subject: Science

#### Structures of the Different Allotropes of Carbon.

Sagar Manilal Chemistry 11b 05-Jan-2004 Structures of the Different Allotropes of Carbon Carbon is a very crucial element as it is there everywhere we see, it even is in our own bodies. Carbon is present in our everyday lives such as in the food and even in air which we use to survive on a regular basis. Diamonds are another form (allotrope) of carbon in is currently the strongest known substance to man. This element is in the 2nd period and 4th group of the periodic table and has a total of 6 electrons with valency of 4 electrons. These outer shell electrons allow us humans to understand its nature and so we know that is shows covalent properties and undergoes covalent bonding. This sort of bonding occurs when the electrons in the outer shell of the element bond with another element by a mean of sharing electrons where electrons are neither lost nor gained in this process. As they have four electrons in the outer shell, it has four covalent bonds as they will have a total of eight electrons with is the total number of electron this particular shell can hold. The covalent bonding in this atom is very special as it forms many diverse crystalline or molecular structures. These different molecular structures of carbon are known as allotropes. An allotrope is the existence of elements in two or more different forms. Carbon has three major allotropes, and they are; diamond,

• Word count: 949
• Level: GCSE
• Subject: Science

#### GCSE Chemistry - Sodium Thiosulphate

We must produce a piece of coursework investigating the rates of reaction, and the effect different changes have on them. The rate of reaction is the rate of loss of a reactant or the rate of formation of a product during a chemical reaction. It is measured by dividing 1 by the time taken for the reaction to take place. There is five factors which affect the rate of a reaction, according to the collision theory of reacting particles: temperature, concentration (of solution), pressure (in gases), surface are (of solid reactants), and catalysts. I have chosen to investigate the effect temperature and concentration have on a reaction. This is because they are the most practical to investigate - it would take longer to prepare a solid in powdered and unpowdered form, and it is difficult to get accurate readings due to the inevitabilities of human errors, and as gas is mostly colourless it is difficult to gauge a reaction changing the pressure, and if a substance is added to give the gas colour, it may influence the outcome of the experiment. Similarly the use of a catalyst complicates things, and if used incorrectly could alter the outcome of the experiment. Aim: - To see the effects of a change in temperature and concentration on the rate of a reaction. The reaction that will be used is: Sodium Thiosulphate + Hydrochloric Acid Na2S2O3 (aq) + 2HCl (aq) Sodium Chloride + Water

• Word count: 2476
• Level: GCSE
• Subject: Science

#### Alkanes, Cracking and Alkenes

Alkanes, Cracking and Alkenes Alkanes Saturated Hydrocarbon (A hydrocarbon compound is a compound made of hydrogen and carbon only.) ) Methane - CH4 (Four single bonds between the carbon (C) and the four hydrogen's (H).) 2) Ethane - C2H6 3) Propane - C3H8 4) Butane - C4H10 5) Pentane - C5H12 6) Hexane - C6H14 7) Heptane - C7H16 8) Octane - C8H18 9) Nanane - C9H20 0) Decane - C10H22 Physical Properties C 1 - C 4 As the number of carbon atoms increase Gases the boiling and melting points also increase. C 5 - C 10 Liquid C 11 + Solid Cracking In the process of 'Cracking', heat breaks bonds between carbon atoms into smaller atoms and it is used to maximise a particular fraction in crude oil As petrol is more needed and most valuable, to increase the fraction of petrol, cracking is used. Such as when Decane is cracked. Which gives us Octane (C8H18), which is saturated because it has four single bonds and Ethene (C2H4), which is unsaturated because it has a double bond (C =

• Word count: 181
• Level: GCSE
• Subject: Science

#### homologous series

Homologous Series * Family of organic compounds * All groups of similar compounds. Have the same functional group * Functional groups defines what they are and how they behave in chemical reactions * Called alkanes, alkenes, ketones, esters, alcohols * All members have same functional group but diff numbers of carbon atoms in chain * No. of carbon atoms in a compound is given by 1st part of its name meth 2 eth 3 prop 4 but 5 pent 6 hex 0 dec * Series name is given by 2nd part of name (like surname) * Alkanes are fully saturated and made of carbon and hydrogen. Their names end in ane e.g.

• Word count: 107
• Level: GCSE
• Subject: Science

#### Empirical Formula Determination

Name: Jonathan Tam Class: 12A Chemistry Experiment report Empirical Formula Determination Aim: To find the empirical formula of Copper oxide Equipment: Bunsen burner Boss Heatproof mat Clamp Combustion tube Delivery tube Retort Stand Mineral paper Method: . Put a square of mineral paper in the combustion tube. Weigh the tube. 2. Add a spatula of copper oxide. Reweigh the combustion tube. 3. Setup the apparatus. Hold the tube in a metal clamp. Join the delivery tube to a gas tap. 4. Turn on the gas tap. Let the gas flow for thirty seconds. Light the gas at the small hole at arm's length. Adjust the gas tap to make a small flame. 5. Strongly heat the copper oxide until a reaction takes place. 6. Turn off the Bunsen burner. Let the gas flow through the tube until it has cooled down. 7. Turn the gas off and reweigh. Diagram: Results: Mass of delivery tube: 50.48g Mass of delivery tube and copper oxide: 57.72g Mass of delivery tube and copper 56.26g Mass of copper oxide 7.24g Mass of copper: 5.78g Analysis: Mass of copper metal: 5.78 Mass of oxygen: 7.24 - 5.78 = 1.46g Mole of copper: 5.78 / 64 = 0.0903 Mole of oxygen: 1.46 / 16 = 0.09125 Ratio: Copper : oxygen 0.0903 : 0.09125 1 : 1.0105... 1 : 1.01 Therefore the ratio of copper to oxygen is 1:1. Conclusion: The ratio of copper to oxygen is 1:1. The empirical formula of copper

• Word count: 260
• Level: GCSE
• Subject: Science

#### Metals.In this presentation I will talk about some examples of metals such as copper, aluminium, steel and mercury and I will discuss with you their properties and how it relates to their use.

We use metals in many different ways. Our lives wouldn't be the same without them, especially living in a country as industrial as Britain. In this presentation I will talk about some examples of metals such as copper, aluminium, steel and mercury and I will discuss with you their properties and how it relates to their use. Properties of Metals * Both heat and electricity flow easily through all metals; therefore they are good conductors of heat and electricity and this is one of the common ways of distinguishing between metals and non-metals. If we know that a substance conducts electricity, then we are almost certain that it is a metal. The only non-metal that conducts electricity well is a type of carbon called graphite. * Metals have a high tensile strength. This means that they are very strong and tough. This is due to the strong bond that exist between the metal particles and that is why they make good building material. * Metals are shiny when polished or freshly cut. They give a strong reflection of light from their smooth surface, which makes them look shiny. * Metals are malleable, which means they can be easily shaped. This is because the bonds inside them are strong, which makes them able to withstand stresses and movement. They are tough and don not shatter easily but we can force a metal to bend into a different shape. * Metals are sonorous; they make a

• Word count: 739
• Level: GCSE
• Subject: Science