In this presentation you will: Distinguish between elements and compounds. Distinguish between pure substances and mixtures. ClassAct SRS enabled.

By definition, matter is everything that has a mass and inertia, and occupies a place in space. It can be simply describe as the “substance” that all things are made of. The way trees, water, the air we breathe, etc. behave, depends on how this substance is formed and its properties. Next >

States of Matter The three states of matter are solid, liquid and gas. The states have both, visible and invisible properties. Solids Shape and volume are defined. Liquids Shape is undefined, but volume is defined. Gases Shape and volume are undefined. Particles are in touch with each other and they form a pattern. Particles are in touch with each other, but they move freely. Particles are apart from each other, moving fast and randomly. Next >

Question 1 Which one of the following correctly describes a solid? A) Defined shape and fixed volume. B) Undefined shape and variable volume. C) Undefined shape and defined volume. D) Defined shape and undefined volume.

Question 2 In which state of the matter are particles moving and in touch with each other? A) Solid state. B) Liquid state. C) Gaseous state. D) All the states.

Pure Substances Every sample of matter is classified as a pure substance or as a mixture. A pure substance is a type of matter in which all samples have the same composition and the same properties. Elements Compounds Pure Substances Mixtures Matter Pure substances are divided in: elements and compounds. Next >

Elements and Atoms An element is a substance that cannot be separated into simpler substances. For example, carbon. Jar containing carbon The smallest particle that preserves the properties of the element is the atom. There is one different type of atom for each element. Carbon atom Next >

Elements and Atoms There are over 100 of these elements. Most of them can be found naturally on Earth. Others are produced synthetically by nuclear reactions. Elements are indicated by symbols, often based on their Latin names. The convention is: The first letter of the symbol is always capitalized. The second and third letters, if any, are never capitalized. Next >

Elements and Atoms Some elements include: Used in: Symbol Name Coins Sodium Coins Salt Rockets Jewelry Fire / Combustion Ag Silver Au Gold O Oxygen H Hydrogen Next >

Question 3 Which one of the following can not be a symbol of an element? A) Mn B) H C) aC D) Na

Compounds and Molecules = Oxygen atom A compound is a substance that is composed of two or more elements chemically held together in fixed proportions. In this example we will look at water. = Hydrogen atom = Molecule of Water Compound of Water In a compound, atoms are chemically combined forming molecules. Next >

Common salt (sodium chloride) Compounds and Molecules Each compound has a chemical formula indicating the proportions each element is combined. Ammonia NH3 Water H2O Common salt (sodium chloride) NaCl One nitrogen atom combined with three hydrogen atoms. Two hydrogen atoms combined with one oxygen atom. One sodium atom and one chloride atom. Next >

Compounds and Molecules The properties of the compounds are different to those of the individual elements. For example, both Oxygen and Hydrogen are gases. But combined, they form water, which is a liquid. H2O Next >

Question 4 Which one of the following is not a compound? A) Sodium Chloride: NaCl B) Magnesium: Mg C) Ammonia: NH3 D) Water: H2O

Mixtures A mixture is the combination of two or more pure substances that do not chemically combine to form compounds. Pure Substances Matter Elements Compounds Mixtures Heterogeneous Homogeneous Mixtures can be divided into homogeneous and heterogeneous. Next >

Mixtures Sand and Pebbles Heterogeneous mixtures are those that are not evenly distributed, the composition of one zone (or phase) is different to the composition of the other zone (or phase). Blood The particles in a heterogeneous mixture are coarse enough to be distinguished by visual observation. Next >

Mixtures Homogeneous mixtures are those that are evenly distributed. The components of a homogeneous mixture are combined together and are unable to be distinguished from one another by visual observation. Next >

Separating Mixtures The components of a mixture usually can be separated by physical means. Basic strategies to separate mixtures: Transfer: add a new phase that collects some components from the mixture, but not others. Conversion: convert components of the mixture into other forms that are easy to isolate. For example to dry clothes, we convert the water into steam. Next >

Question 5 Which one of the following is a mixture? A) water B) orange juice C) vinegar D) salt

Question 6 When using a paper filter to separate sand from water, we are applying a transfer strategy for separating mixtures. Is this true or false? Answer True or False.

Question 7 When evaporating the water of wet clothes to obtain dry clothes, we are applying a transfer strategy for separating mixtures. Is this true or false? Answer True or False.

Summary After completing this presentation you should be able to : Show knowledge and understanding of the properties of each of the three states of matter. Distinguish between elements and compounds. Distinguish between pure substances and mixtures. End >