Changes in Matter Review 9th

PHYSICAL PROPERTIES Characterize the physical _____and physical _________of a substance Each substance has unique physical properties Examples – Sulfur appears as a yellow powder – The boiling point of water is 100 o C – Carbon monoxide is odorless

CHEMICAL PROPERTIES Describe ways pure substances behave when interacting with _______________________ Examples – Iron reacts with oxygen to form rust. – Platinum does not react with oxygen at room temperature.

Chemical vs. Physical Change – _______________: A change that can occur without changing the identity of the substance. – Ex. Solid, Liquid, Gas (Phase change) – ______________: Process by which a substance becomes a new and different substance – Ex. Fire

STATES OF MATTER Solid Liquid Gas Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

WATER AND ITS STATES OF MATTER

CHANGES IN STATE Melting: Solid to liquid Boiling: Liquid to gas ___________: Solid to gas – The above three require input of energy _____________: Gas to liquid Freezing: Liquid to solid ____________: Gas to solid – The above three release energy

PHYSICAL CHANGES ____________ the chemical _________ of the substance – Examples include: Any change in the state of matter (e.g. freezing or boiling water) Sawing wood Crushing a tablet Bending a wire Dissolving salt in water

CHEMICAL CHANGES ________ the ________ of the substance as the chemical composition changes. – Also called ____________________ Examples: – Tarnishing of silver (Ag forms AgS) – Rusting of iron (Fe forms Fe 2 O 3 )

Chemical Reactions Chemical Reaction: a process in which the physical ____ chemical properties of the original substance ________as new substances with different physical and chemical properties are formed Chemical Reaction: a process in which the physical ____ chemical properties of the original substance ________as new substances with different physical and chemical properties are formed

CHEMICAL REACTIONS Are expressed using ___________________. Rusting of iron: 4 Fe + 3 O 2  2 Fe 2 O 3 (rust) reactants products Meaning: Four atoms of iron react with three molecules of oxygen to form two molecules of rust

Mixtures and Solutions

A mixture is a combination of __________________that are NOT ___________________, and retain their identities. Mixtures ______ physically _________. The identities of the substances DO NOT change. A homogeneous mixture is also called a solution.

Mixtures When a mixture’s components are easily recognizable, such as pizza, it is called a ______________mixture. In a _____________mixture such as chocolate milk, the component particles cannot be distinguished, even though they still retain their original properties.

TYPES OF MIXTURES Heterogeneous Mixtures – A mixture that does not blend smoothly throughout – Individual ______________________ from one another Exe: Salad Dressing, fresh squeezed OJ Homogeneous Mixtures – Has _________ composition – Single phase – AKA: Solutions Exe: Chocolate Milk, Steel,

Separating Mixtures Common Techniques for Separating Mixtures ____________ – separates a mixture based on boiling points of the component. Examples : saltwater crude oil into gasoline and kerosene Magnet – separates _____ from other objects. ___________– spins and separates according to ___________.

Solutions A mixture that appears to be a single substance but is ___________________ ______________________ that are distributed evenly amongst each other. A solution may be liquid, gaseous, or solid. Examples of solutions Liquid - seawater Gas - air Solid - alloys

Solutions __________ – The process in which particles of substances separate and spread evenly amongst each other. _______– substance that is _________. A solute is soluble, or able to dissolve. Exe: Sugar A substance that is insoluble is unable to dissolve, forms a mixture that is not homogeneous, and therefore NOT a solution. _______– substance in which solute dissolves into. Exe: Water

Solubility Solubility is the ___________ solid, liquid, or gaseous chemical substance called a ________ to ____________ a solid, liquid, or gaseous ________to form a homogeneous solution of the solute in the solvent. The solubility of a substance determines the __________________________ make a _________solution using a given amount of solvent at a certain temperature. Solubility is usually expressed in grams of solute per 100 ml of solvent (g/100ml) What does saturated mean? Three (3) methods that affect solubility – Mixing, stirring, or shaking – Heating – Crushing or grinding

Suspension A mixture in which __________of a material are dispersed through- out a liquid or gas but are ________ ______________________________. – Particles are ___________, so they DO NOT dissolve in the liquid or gas. – Particles can be separated using a filter. Examples: Salad dressing Medicines that say “shake well before use”

Colloids A mixture in which the _________are dispersed throughout but are _________ _______________________________ out. Made up of solids, liquids and gases. –E–Examples : Mayonnaise Stick deodorant milk

CLASSIFICATION OF MATTER

ELEMENTS ________________ that contain only one type of atom The smallest building blocks of pure substances are called _________ There are 115 known elements today, 90 which occur naturally The periodic table displays the elements

The Periodic Table (+/-)

ELEMENTS (Cont) Each element has a unique symbol – The _____________ is always ___________, the _________ letter is always ________ case Fluorine is F, not f Cobalt is Co, not CO (which is carbon monoxide) The smallest unit of an element is the atom

COMPOUNDS Substances containing ______________ type of atom bonded together in fixed ratios. – NaCl (table salt) Contains sodium (Na) and chlorine (Cl) NaCl is the chemical formula – H 2 O (water) Contains 2 atoms of hydrogen (H) and 1 atom of oxygen (O) H 2 O is the chemical formula Elements in compounds are combined in a _________________. – H 2 O is water but H 2 O 2 is hydrogen peroxide

COMPOUNDS (cont) Are the molecules H 2 and O 3 considered elements or compounds? Why?

CLASSIFICATION OF MATTER Classify the following as an element, compound, homogeneous mixture, or heterogeneous mixture. a.Fog b.Gasoline c.Helium d.Sulfuric acid (H 2 SO 4 ) e.Orange juice from squeezed oranges

CLASSIFICATION OF MATTER Classify the following as an element, compound, homogeneous mixture, or heterogeneous mixture. a.Fog b.Gasoline c.Helium d.Sulfuric acid (H 2 SO 4 ) e.Orange juice from squeezed oranges

CHEMICAL REACTIONS (Cont) Zn + 2 HCl  ZnCl 2 + H 2 Zinc hydrochloric acid zinc chloride hydrogen gas Meaning: One atom of zinc reacts with two molecules of hydrochloric acid to produce one molecule of zinc chloride and one molecule of hydrogen gas.