UNIT B/ Chemistry 6.1

W HAT IS CHEMISTRY ANYWAY ?! Chemistry is... The study of the properties, composition and behaviour of matter… MATTER is anything that has _____________ and occupies a ______________

P ROPERTIES, COMPOSITION AND MATTER Property is a characteristic, a trait or quality that something has Ex: water boils at 100 °C Composition is what something is made up of…its basic nature from the inside (its ingredients) EX: water is made up of two hydrogen atoms and 1 oxygen atom  H 2 0.

THE PHYSICAL PROPERTIES OF MATTER Substance is something unique with a set of unique properties. Properties of matter PHYSICAL vs CHEMICAL PROPERTY PROPERTY/Rxns It is a property that can be observed and found without creating a new substance. Or changing the chemical structure of it Ex: colour, density, hardness, melting point, boiling point, pH, viscosity, etc… It is when a new substance is created due to undergoing chemical reactions. Ex: hydrogen can burn in air (Oxygen) and produce water Hydrogen reacts with chlorine to produce hydrogen chloride.

CLASSIFICATION OF MATTER Atom: The smallest part of an element which retains ALL the fundamental properties of the element… Elements - contain only one type of atom 1. monatomic elements consist of 1 atom only ex: Fe, Al, Cu, He 2. polyatomic elements consist of several “like” atoms bonded together Ex: H 2 O 2 Br 2 F 2 I 2 Cl 2 P 4 S 8

D IATOMIC ELEMENTS H 2 O 2 Br 2 F 2 I 2 Cl 2

CLASSIFICATION OF MATTER A molecule is 2 or more atoms held together If a molecule is made up of identical atoms, it is called an element. If a molecule is made up of different types atoms, it is called a compound. Atoms are held together by electrical forces.

CLASSIFICATION OF MATTER Difference between an element and a compound? First, they are both molecules (2 or more atoms) An element is made up of the same type of atoms A compound is made up of different types of atoms.

CLASSIFICATION OF MATTER ION : atom or molecule that possesses an electrical charge… Sodium ion (Na + ) Chloride ion (Cl - ) Nitrate ion or Nitrate ( NO 3 - ) More about this soon!

M ORE TERMS TO CLASSIFY MATTER Pure substance : unchanged, uniform properties. Ex: salt (NaCl) has a density of 2.16 g/mL and melts at 801 C and is colourless. A pure substance has Identical properties in every sample..

More on substances Pure Substances: a substance that is made up of only one kind of matter. There are two kinds of pure substances: a)Element - a pure substance that cannot be broken down or separated into simpler substances Ex: gold (Hg) silver(Ag) b) Compound - a substance composed of at least two elements Ex: water (H 2 0), CO 2

MIXTURES A mixture: a system made up of 2 or more substances, and the amounts can be different/varied. Ex: salt dissolved in water.

H OMEWORK 6.1 Page 152 2, 9,10