symbol, eg ‘O’ represents an atom of oxygen. There are about 100 different elements. Elements are in the periodic table. Compounds are formed from elements by chemical reactions. Chemical reactions always involve the formation of one or more new substances, and involve a detectable energy change. Compounds contain two or more elements chemically combined in fixed proportions and can be represented by formulae using the symbols of the atoms from which they were formed. Compounds can only be separated into elements by chemical reactions. Chemical reactions can be represented by word Name compounds of these elements from given formulae or symbol equations. Write word equations for the reactions in this specification. Write formulae and balanced chemical equations for the reactions in this specification. (HT only) balanced half equations and ionic Use scientific conventions to identify elements by chemical symbols. Define a compound. Write word equations for reactions from practical activities stated in the specification. Develop skills to communicate through use of symbolic equations. Apply these skills to write balanced symbol equations for equations met in practical activities. Extended writing Describe word, formulae and balanced chemicals equations. Construct an element fact file or cube. Discussion about the difference between atoms, elements and compounds. Model atoms, elements and compounds. Burn magnesium in oxygen. Burn sodium in oxygen. Video clip: BBC Bitesize to atoms and elements (interactive)
equations or equations using symbols and formulae. equations where appropriate. 5.1.1.2 A mixture consists of two or more elements or compounds not chemically combined together. The chemical properties of each substance in the mixture are unchanged. Mixtures can be separated by physical processes such as filtration, crystallisation, simple distillation, fractional distillation and chromatography. These physical processes do not involve chemical reactions and no new substances are made. Describe, explain and give examples of the specified processes of separation. Suggest suitable separation and purification techniques for mixtures when appropriate information. 2 Define a mixture. Extended writing Describe each practical technique of separating mixtures. Explain how chromatography, distillation and filtration practical techniques High demand Explain why crystallisation happens. mixtures. WS 2.2, 2.3, 4.1 Carry out chromatography techniques using sweets or felt tip pens. Demo distillation of citrus peel. Carry out crystallisation using salol. Carry out filtration and evaporation of sea water. Show that mineral waters are not ‘pure’ in the scientific sense. Video clip: BBC Bitesize and compounds 5.1.1.3 New experimental evidence may lead to a scientific model being changed or replaced. Before the discovery of the electron atoms were thought to be tiny spheres that could not be divided. The discovery of the electron led to the plum-pudding Describe how and why the atomic has changed over time. Describe the difference between the model of the atom and the nuclear model of the atom. Describe why the new evidence from the 1 Create a timeline for the history of the atomic Extended writing Describe the differences between the plum-pudding model, nuclear model and atomic model. Describe why changes to the atomic model happened. Model the plum-pudding model, nuclear model and atomic model. WS 1.1, 1.2
5.1.1.6 The relative atomic mass of an element is an average value that takes account of the abundance of the isotopes of the element. Students should be able to calculate the relative atomic mass of an element given the percentage abundance of its isotopes. 0.5 YouTube: 5.1.1.7 The electrons in an atom occupy the lowest available energy levels (innermost available shells). The electronic structure of an atom can be represented by numbers or by a diagram. For example, the electronic structure of sodium is 2,8,1 or showing two electrons in the lowest energy level, eight in the second energy level and one in the third energy level. Students should be able to represent the electronic structures of the first twenty elements of the periodic table in both forms. Students may answer questions in terms of either energy levels or shells. 0.5 Describe how many electrons there can be in the first, second and third energy shells. Role play – using students to represent protons, neutrons and electrons, build up the idea of full and complete energy shells with 2 in the first, 8 in the second and 8 in the third energy shell. WS 1.2 Ma 5b YouTube: YouTube:
5.1.2 The periodic table Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to develop and apply practical and enquiry skills Self/peer assessment opportunities and resources Reference to past questions that indicate success 5.1.2.1 The elements in the periodic table are arranged in order of atomic (proton) number and so that elements with similar properties are in columns, known as groups. The table is called a periodic table because similar properties occur at regular intervals. Elements in the same group in the periodic table have the same number of electrons in their outer shell (outer electrons) and this gives them similar chemical properties. Explain how the position of an element in the periodic table is related to the arrangement of electrons in its atoms and hence to its atomic number. Predict possible reactions and probable reactivity of elements from their positions in the periodic table. 0.5 Identify link between electron configuration and the structure of the periodic table for elements 1 to 20. Identify anomalies. clip: BBC Bitesize – Groups and periods in the periodic table YouTube: YouTube: Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to develop and apply practical and enquiry skills Self/peer assessment opportunities and resources Reference to past questions that indicate success 5.1.2.2 Before the discovery of protons, neutrons and electrons scientists attempted to classify the elements by arranging them Describe these steps in the development of the periodic table. 0.5 Create a timeline for the history of the periodic Extended writing WS1.1 or (interactive)
5.1.2.5 The elements in Group 1 of the periodic table are known as the alkali metals and have characteristic properties because of the single electron in their outer shell.: In Group 1, the reactivity of the elements increases going down the group. Describe the reactions of the first three alkali metals with oxygen, chlorine and water. Explain how properties of the elements in 1 depend on the outer shell of electrons of the atoms. Predict properties from given trends down the group. 0.5 Extended writing Describe the trends in properties in 1. Explain how properties of the elements in Group 1 depend on the outer shell of electrons of the atoms. High demand Explain the trends in Group 1. Demo reactivity of Na, Li and K in water with universal indicator. Predict reactions for Rb, Cs and Fr. Video clip: YouTube: YouTube: Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to develop and apply practical and enquiry skills Self/peer assessment opportunities and resources