UNIT 1 Foundations

1. UNIT 1 Foundations Chapter 2 - MATTER

2. Chapter 2A – The Particle Model of Matter • Objectives: • Describe matter • Summarize the particle model of matter • Contrast Brownian motion and diffusion • Discuss evidences for the particle model of matter • Use the kinetic-molecular theory to explain Brownian motion and diffusion • Diagram the parts of an atom • Show how ions and molecules form using the parts of an atom. • Assignment: Section Review, page 34

3. Describing Matter • What is matter? • All substances that occupies a volume of space and has mass • Can be sensed and measured • Measurable mass, measurable weight • Made up of particles • Solid, liquid, gas, and plasma • What is plasma?

4. The Particle Model • Four hundred years before Christ… • Greek philosophers started discussing the nature of matter • Was in continuous, was it not continuous • Called “atomos”, meaning indivisible • How does ones worldview affect the role of science? • Facet • One of numerous aspects, as of a subject • A side, aspect, or point of view • Particle Theory (Model) • All matter is made of exceedingly small particles • Diameter of a typical particle is measured in nanometers, very small metric unit

5. The Particle Model • These particles are referred to as atoms • Building blocks of matter • Combine to form molecules • The basic particle of matter from which all other matter is constructed, consisting of protons, electrons and neutrons. • How do we know? • Scientists can see them using a scanning tunneling electron microscope (STM) • Properties associated with matter • Color, density, electrical conductivity can’t be seen in each individual particle, it is how they function together

6. Evidence for the Particle Model • Atoms are held together by bonds • a connection by sharing or transferring electrons to form larger structures like molecules • How do we know these particles exist? • Particles can be observed by color and taste • Particles are in constant motion • Diffusion – the process of spreading out and mixing due to particle motion • Brownian motion – microscopic, random jostling of suspended matter due to the collisions of innumerable gas or liquid particles in which the matter is suspended. • All of this makes up the kinetic-molecular theory of matter.

7. Particle Model • Summary of the four main ideas of the particle model • All matter is made of particles • Particles are always moving • There are spaces between particles • Particles are attracted to one another • One of the most useful theories ever proposed in science • Predicts the behavior of the states of matter as well as explains pressure, diffusion and conductivity

8. The Atom • Let’s review what an atom is: • The basic particle of matter from which all other matter is constructed, consisting of protons, electrons, and neutrons.(subatomic particles) • Nucleus at the center • Nucleus contains protons and neutrons and makes up the mass of the atom • Proton is positively charged, neutron has no charge but the same mass as the proton • The number of protons determines the type of atom or element • Electrons are negatively charged, occupies the spherical volume and has insignificant mass compared to the proton and neutron • Electrons determine the size of the atom and are equal in number to the proton so the atom has no charge

9. Molecules • Molecules • Distinct particles formed when two or more atoms bond together • Can be simple like oxygen • Can be large and complex like DNA

10. Ions • Atoms can gain or lose electrons forming ions • An atom or molecule that has gained or lost electrons, thus producing an imbalance between the number of protons and electrons in the particle • Anions • Gained electrons, have a negative charge • Cations • Lost electrons, have a positive charge • Ions form matter and can be attracted and repelled by an electric current

11. Chapter 2B – Classification of Matter • Objectives: • Classify examples of matter • List the common states of matter and give examples of each • Compare and contrast the three common states of matter • Explain the differences in the three common states of matter using the kinetic-molecular theory • Explain what causes viscosity and gas pressure using the kinetic-molecular theory • Assignment: Section Review, page 40

12. The Classification Model • Classifications help us to understand our surroundings, they organize into familiar patterns • Classification has been around since the beginning of creation • Adam named all the animals • Matter needs to be classified more than just solid, liquid, and gas

14. Pure Substances • Pure substances • Matter that contains only one kind or atom or a fixed ratio of different atoms • Element • One kind of atom containing all the same number of protons in their nuclei • Periodic table contains all known elements thus far • Compound • Two or more elements bonded in a fixed ratio • Inorganic – usually do not contain carbon • Organic – contain carbon and are produced by living things • Not all compounds that contain carbon are organic • Other elements present are hydrogen, nitrogen, phosphorus, oxygen

15. Mixtures • Mixtures • Combinations of two or more substance • Elements, compounds or other mixtures • Mixtures are not bonded together • Two types of mixtures • Heterogeneous • Non-uniform mixture that contains two or more distinct phases, usually of different kinds of matter • Homogeneous • A uniform mixture of particles of different substances that form a single phase, also called a solution

16. States of Matter • State • A physical form of matter determined by the arrangement and energy of its particles: solid, liquid, gas

17. Solids • Characteristics of a Solid • Definite volume • Definite shape, rigid • Low compressibility • Particles are close together and vibrate in fixed positions • Types of solids • Crystalline • Particles in a fixed, repeating structure • Quartz, sugar, salt • Amorphous • Particles arrangement is fixed, but random • Glass, wax • Heterogenous • Particles are fixed, some order • Wood, bone

18. Liquids • Characteristics of a Liquid • Definite volume • No definite shape, assume the shape of the container they are in • Forms a free surface if it does not completely fill its container • Low compressibility • Particles are completely mobile but still close together due to mutual attraction • Collide randomly and vibrate individually • Exhibit properties of viscosity • A measure of a fluid’s resistance to flow, the “thickness” of a liquid • lubricants

19. Gases • Characteristics of a Gas • Indefinite volume • Indefinite shape • Highly compressible • Particles are far apart and move at high speeds • Collide in straight lines and vibrate individually • Gases can flow! • Fluids • A substance that can flow, a liquid or gas • Gas pressure • The pressure a fas exerts on its container or on an object immersed in it

21. Chapter 2C – Changes in Matter • Objectives: • Identify physical and chemical properties for a specific type of matter • Classify changes in matter as physical or chemical changes • Paraphrase the law of conservation of matter • Compare and contrast physical, chemical, and nuclear changes in matter • Assignment: Section Review, page 46

22. Unusual States of Matter • Open to page 41, we will read the facet together… • Vocabulary • Plasma • a gas-like substance formed at very high temperatures that consists of high-energy ions • Bose-Einstein condensate (BEC) • A state of matter that can form near absolute zero (0K) when atoms slow their motion enough to merge into a single “super atom” • Quark-gluon plasma (QGP) • High-temperature state of matter that forms when nuclei collide with such energy that their protons and neutrons are broken down into a “soup” of elementary particles called quarks and gluons.

23. Physical Properties and Changes • Physical property • Any feature that can be observed or measure without altering the kind of matter being studied • Examples are color density, hardness, crystalline form, electrical conductivity, texture, physical state • Tells us what type of matter is better to use • A diamond drill bit, or a quartz drill bit? • Physical change • A change that does not alter the composition of the material • Particles can rearrange, but not change • Water, wood, sugar

24. Chemical Properties and Change • Chemical properties • A feature of a substance that describes how its chemical identity changes in the presence of another substance • Iron • Stainless steel • Chemical Change • Any change in a substance that alters its composition, the kind and ratio of elements in the substance • Also referred to as a chemical reaction • Bonds are broken and new ones formed

25. Using Properties of Matter to Solve Problems • Bulletproof Vests • Made of Kevlar because of its physical property of strength • Five times that of steel • The strength comes from the chemical properties of its molecular structure • Made of long polymers consisting of smaller repeating groups of atoms • Loses strength in the presence of water or ultraviolet light so it is covered with a protective substance

26. Conservation of Matter • Law of Conservation of Matter • Matter can be neither created nor destroyed, but only changed from one form to another • Antoine Lavoisier is credited with being the first to confirm this law in 1785

27. Nuclear Changes • In physical and chemical changes the kinds of atoms involved always remain the same • Nuclear change • The change in the energy or composition of an atom’s nucleus when it emits or absorbs nuclear radiation • Forms totally different atoms • Takes place in nuclear power plants and nuclear bombs

28. Chapter 2D – Changes of State • Objectives: • List the types of changes matter can undergo • Relate temperature with change of state • Discuss the factors that affect vaporization • Explain each change of state using the kinetic-molecular model of matter • Assignment: Section Review, page 51

29. Changes of State and Temperature • Phase change or change of state • When matter changes from one state to another, especially when two or more states are present at the same time • Motion of particles is directly related to the temperature • One goes up so does the other • Thermal energy • Related to the random vibrations and motions of the particles in a substance

30. Melting and Freezing • Melting • The change of state from a solid to a liquid when thermal energy is absorbed • Melting point • The temperature at which a pure solid turns into a liquid at 1 atm; the same temperature as the freezing point • Freezing(solidifying) • The change of state from a liquid to a solid when thermal energy is released • Freezing point • The temperature at which freezing occurs at 1 atm; the same temperature as the melting point

31. Vaporization and Condensation • Vaporization • Any process in which particles of a liquid enter the gaseous phase • Vapor • The gaseous phase of a substance • What’s the difference between a gas and a vapor? • Vapor pressure • The gas pressure exerted on the surface of a liquid by its vapor in a close container when the gas and liquid are in equilibrium

32. Vaporization and Condensation • Three types of vaporization • Boiling • Rapid vaporization that occurs when a liquid’s vapor pressure equals or exceeds atmospheric pressure and the static pressure in the liquid, forming vapor bubbles • Boiling occurs at the boiling point and throughout the whole liquid • The temperature and pressure at which boiling occurs

33. Vaporization and Condensation • Evaporation • Relatively slow vaporization that occurs when a liquid’s temperature is below its boiling point, but above its freezing point • Evaporation occurs at the liquid’s surface • A method of cooling • Sweating

34. Vaporization and Condensation • Sublimation • The change of state from a solid directly to a vapor at temperatures below the melting point of the substance • Dry ice, mothballs, solid air fresheners • Deposition(not in book) • The change of state from a gas(vapor) directly to a solid

35. Vaporization and Condensation • Condensation • The change of state from gas to liquid when thermal energy is released to the surroundings • Opposite of vaporization • Dew • Watering in the Garden of Eden • Page 51

36. TOMORROW!!! • Vocabulary Quiz • Includes all vocabulary throughout the entire chapter, PowerPoints, and front board; not just the box at the end. • Complete Chapter Review in Class; EXCEPT #31, #32 • Study for Chapter 2 Test