Elements ,compounds, and mixtures

1. Elements ,compounds, and mixtures Abdul Malik SR SMPN 1 Lamongan

2. BasicCompetency:To understand the element, compound and mixture.Standard Competency:Describes concept of element, compound and mixture • 1.To describe the characteristics of elements, compounds, and mixtures • 2.To classify matters into elements ,compounds ,and mixture Objectives

3. Science words • Elements • Compounds • Mixtures • Homogenous • Heterogeneous

4. What is Matter…??? • Matter -anything that has mass and take any space Matter = zat

5. Elements • Element is single matter that cannot be broken down into simpler matter by chemical methods. • There are 116 known elements. Of these 92 are found in the Earth (natural). The other 24 elements have been made by scientist in laboratories (manmade). Examples of element: silver Fluorine Gold Aluminium Mercury

6. The Symbol of element • Jons Jacob Berzelius proposed alphabets as the symbols of each element. • All of elements use symbol. These symbols were taken one or two letters from their old Latin or Greek name. Example: Au is the Latin word of gold “Aurum”. • Rules of writing element symbols: • 1. If an element is symbolized by one letter, it must be capital letter, for example oxygen (O), hydrogen (H), carbon (C). • 2. If an element is symbolized by more than one letters, the first letter must be capital letter followed by small letter, for example zinc (Zn), gold (Au), copper (Cu).

7. Think Time • What are the chemical symbols of the following elements? • Bromine • Silver • Uranium • Antimony • Tungsten • What are the names of the elements with the following chemical symbols? • Si • P • Sn • Pb • Au

8. Classification of the Elements • Classification of elements by state • Elements can be classified by their physical state at room temperature • Solid (of the 92 natural element, 79 are solids) • Gas (of the 92 natural element, 11 are gases) • Liquid (of the 92 natural element, 2 are liquid) Chlorine gaseous element Silver solid element Bromine liquid element

9. Classification of elements as metals and non-metals • Elements are classified as metals and non-metals, depending on how well they conduct electricity and heat. • Metals are good conductorsandNon-metal very poor electrical conductors. • Some elements are classified as Metalloids(or semi-metals). Metalloids have properties between those of metals and non metals. Metalloid metal Non - metal carbon sulphur lead boron silikon neon mercury chlorine copper Noble gases

11. Classification of elements as in the periodic table

12. What are element made of? • Atoms An atom is the smallest unit of an element, having properties of that element. The atoms of one element are different from the atoms of any other element. • For example, all hydrogen atoms are the same and are different from atoms of carbon or iron. • Molecules Most gaseous elements form molecules comprising two atoms. Example: • Oxygen (O2), • Hydrogen (H2), • Nitrogen (N2), • Chlorine (Cl2) N2 Gases + N N N N

13. Post test Answer this question. • Define an element. • State the names and symbols of some common elements. • Describe ways of classifying the elements.

14. You can visit this website www.chem4kids.com

15. COMPOUND • Compound is a substance containing two or more elements chemically joined together. • If elements combine together, they will completely change. For example: • Water (H2O) is a compound made up of Hydrogen and Oxygen. Hydrogen and Oxygen are colourless gases, and the compound water is colourless liquid + O O H H H H

16. Compound is a single matter that cannot be broken down by physical separation. The compound can only be broken down into its elements by a chemical reaction. • Molecules is the smallest particle of a compound. • A compound contain only one kind of molecule. • Molecule is a group of two or more atoms chemically joined together. What are Compound made of?

17. Chemical formula of a molecule The chemical formula of a molecule shows the number and kinds of atoms contained in it. The chemical formula for water is This formula tells us that a water molecule contains 2 hydrogen atoms and 1 oxygen atom Symbol of atom H2O The amount of atoms present in one molecule

18. Think Time • State the number of atoms and name the kinds of atoms shown by each formula • Alcohol, C2H5OH • Refined sugar, C12H22O11 • Sulphuric acid, H2SO4 • Sulphur dioxide, SO2 • Glucose, C2H12O6 • Urea, CO (NH2)2

19. Names of compound • Many compound contain a metal and a non-metal. The metal part usually comes first, followed by the non-metal part. • For example: NaCl (sodium chloride) • The names of many compounds with only two elements often end in –ide. • For example: MgO (magnesium oxide) • If the name of compound end in –ate, they contain oxygen. • For example: CaCO3 (Calcium Carbonate) • Acids are compounds. Their names usually end in –ic acid. • For example: HCl (Hidrochloric acid)

20. These are some of the chemical formula

21. Chemical reaction between hydrogen and oxygen producing water • Calculate the comparison between the mass of hydrogen and oxygen in water compound. What is the result? • What will happen if the mass of hydrogen and oxygen reacting does not follow the comparison? • What can you conclude about the comparison of elements in the compound?

22. Conclusion • Water was compound by hydrogen and oxygen with ratio of 1:8 (1 for hydrogen and 8 for oxygen) • If the ratio of H:O was not equal to 1:8, there would be an excess element (sisa) • The mass of elements before and after a reaction was CONSTANT PROUST’s law “The mass ratio of elements of a compound component is constant” (Perbandinganmassaunsur-unsurpenyusunsenyawaadalahtetap)

23. Think Time Answer: • The comparison for the mass of hydrogen and oxygen is 1:8 • When 4 grams of hydrogen react with 16 grams of oxygen, how many grams of water are produced? If there is an excess, determine the element and it mass

24. Mixtures • In the world, there are many things that’s not pure substances. • Mixtures consist of two or more substances that are notchemically joinedtogether. • Mixtures can consist of elements, compound or both. Also the substances in a mixtures may be solids, liquids or gases Sea water is mixture of compounds including water and sodium chloride Brass is a mixture of the elements copper and zinc

25. Classification of mixtures • The prefixes "homo"- indicate sameness • A homogeneous mixture has the same uniform appearance and composition throughout. Many homogeneous mixtures are commonly referred to as solutions. • The prefixes: "hetero"- indicate difference. • A heterogeneous mixture consists of visibly different substances or phases. The three phases or states of matter are gas, liquid, and solid. Heterogeneous Homogeneous In sugar solution, sugar is the solute and water is the solvent

26. Differences between compound and mixtures

27. Can you Distinguish elements, compounds and mixtures? What matter are beside? It’s elements… Why? N N N N N N N

28. Then, what matter are beside? • Its compound… • Why? Cn Cn s S s Cn Cn s

29. Next, what matter are beside? Its mixture… Why? s Cn s Cn s s Cn s