Physics and Matter

By Prof. Liwayway Memije-

Cruz

Physics• the study of

everyday phenomena using the fundamental laws of nature.

• the study of matter and energy and their relationship.

Branches of Physics

Classical Physics• MECHANICS – the study of forces acting on bodies whether at rest or in motion

Branches of Physics• Classical Physics – the traditional

forces that were recognized and developed before the beginning of the 20th century

• Modern Physics – to the concepts in physics that have surfaced since the beginning of the 20th century.

Subdivisions of Mechanics1. Statics – study of

the forces on a body or bodies ar rest.

2. Dynamics - study of motion and the forces that affect it.

3. Kinematics - study of motion without regard to its causes

Optics• the study of light• concerned not only

with visible light but also with infrared and ultraviolet radiation, which exhibit all of the phenomena of visible light except visibility, e.g., reflection, refraction, interference, diffraction.

Acoustics /Sound Physics• the study of sound, is

often considered a branch of mechanics because sound is due to the motions of the particles of air or other medium through which sound waves can travel and thus can be explained in terms of the laws of mechanics. Ultrasonics  - the study of sound waves of very high frequency, beyond the range of human hearing.

Heat• Heat is a form of

energy, the internal energy possessed by the particles of which a substance is composedThermodynamics - deals with the relationships between heat and other forms of energy.

Electromagnetism- the study of the properties of electric current and magnetism and their relationship

a. Electrostatics – on electric charges at rest

b. Electrodynamics– on moving charges

c. Magnetostatics – on magnetic poles at rest

Modern Physics1. ATOMIC and NUCLEAR PHYSICS – the

study of the components, structure and behavior of the nucleus of the atom.

2. QUANTUM PHYSICS – the study of the discrete nature of phenomena at the atomic and subatomic levels its focus is on the invisible units of energy called quanta as described by the quantum theory.

3.RELATIVISTIC PHYSICS - the study of phenomena that take place in a forms of reference that is in motion with respect to an observer.

4.SOLID STATE PHYSICS – study of all properties of solid materials including electrical conduction in crystals of semi-conductor and metals.

5. CONDENSED MATTER PHYSICS –study of the properties of condensed materials (solids, and liquid and those intermediate between them and dense gas) with the ultimate goal and developing new material with better properties; it is an extension of solid state physics.

6. PLASMA PHYSICS –the study of the fourth state of matter; plasma

7. LOW TEMPERATURE PHYSICS – the study of the production and maintenance of temperatures down to almost absolute zero and the various phenomena that occur only at such temperature.

Matter

Matter is anything that occupies space and has mass

Classification of MatterAccording to the origin or source, matter is classified as

organic and inorganic matter. Organic matter comes from living things, while inorganic matter comes from non-living things.

Chemists have studied that all forms of matter may be classified into three general classes on the basis of their compositions. These are the elements, compounds and mixtures.

Element is a substance, which cannot be decomposed by ordinary means. Atom is the smallest part of an element that can enter into combination with other elements.

Compound is a substance, which can be decomposed into two or more simpler substances by ordinary chemical means.

Mixture is a material composed of two or more substances each of which retains its own characteristic properties. a. Heterogeneous mixture is one which has parts possessing different properties. b. Homogeneous mixture is one which has similar properties throughout. Substance is a homogeneous material composed of one particular kind of matter.

Matter can ordinarily exist in three physical states –solid, liquid, and gas. A fourth state of matter exists under special conditions, called plasma.

The state of matter changes as you add more energy.

Changes in matter

Physical Properties

Specific properties are those features, which definitely distinguish one substance from another. Some of these are the following:

1. Density is the weight of a unit volume of a substance.2. Specific gravity is the ratio of the weight of a given volume

of a substance to the weight of the same volume of water at the same temperature.

3. Hardness is the ability of the substance to resist scratching.4. Odor is the characteristics odor of a given substance.5. Color is the characteristics color of a given substance.

Accidental physical properties are those features as weight, dimensions, and volume. They have nothing to do with the nature of the substance, but they enable us to find out how much of a given substance we have.

Specific and accidental

Chemical PropertiesChemical properties of a substance describe

how a substance acts when it undergoes change. They describe its ability to form new substances under given conditions.

A chemical change or a chemical reaction is a change from one substance to another. the reactions occur. Some of the chemical properties are: combustibility, stability, relative activity, response to test reaction, and ionization.

States of Matter and Changes of State.

Intrinsic and Extrinsic Properties• Intrinsic (intensive) Properties are

properties that do not depend on the size of the sample. Examples are color, odor, boiling point, and electrical conductivity.

• Extrinsic (Extensive) Properties are properties that depend on the size or amount of the sample. Examples are mass and volume.

Law of Conservation of Mass• The Law of Conservation of Mass state that

mass is neither created nor destroyed. An example is shown in the complete combustion of gasoline. The relationship is true within the limits of one’s ability to determine the weights of the reacting substances and the products of the reaction:

Gasoline + oxygen ----> carbon dioxide + water vapor

Weight of reactants = weight of products

Identify whether the following are physical or chemical changes:• ___________________1. welding metals• ___________________2. ripening of fruits• ___________________3. grinding rice• ___________________4. dissolving sugar in

water• ___________________5. burning gas• ___________________6. magnetizing iron nails• ___________________7. melting of butter• ___________________8. hair bleaching• ___________________9. souring of milk• ___________________10. brewing of coffee

Classify the following as either an element, a compound, or a mixture:• ___________________1. gasoline• ___________________2. dry ice• ___________________3. aluminum wire• ___________________4. diamond• ___________________5. lead pencil• ___________________6. toothpaste• ___________________7. penny• ___________________8. platinum• ___________________9. glue• ___________________10. rubbing alcohol

Classify the following properties as intrinsic or extrinsic:• ___________________1. volume• ___________________2. density• ___________________3. length• ___________________4. color• ___________________5. freezing point• ___________________6. electrical conductivity• ___________________7. mass• ___________________8. odor• ___________________9. boiling point• ___________________10. luster

Kinetic Molecular Theory• shows how individual gas

particles interact with one another.

Assumptions of KMT:• Molecules are point masses

(they have no volume)• Gas molecules exert no force

on each other unless they collide

• Collisions of molecules with each other or the walls of the container do not decrease the energy of the system

• The molecules of a gas are in constant and random motion

• The temperature of a gas depends on its average kinetic energyavg(1/2mv 2) = 3/2kT . In other words, the energy of an ideal gas is entirely kinetic.

Cohesion and AdhesionCohesion - refers to the attraction between like molecules.Adhesion – refers to the attraction between unlike molecules.

Cohesion in Solids• Tenacity – the ability

of a material to resist being pulled apart. Ex…steel, tungsten, iron and bronze

• Malleability – the state of being malleable, or capable of being shaped, as by hammering or pressing

• Ductility - the ability of material, such as steel, to be drawn out into thin wires or flat sheets without pulling apart or breaking. Materials that are extremely ductile can be stretched thin without cracking and losing their strength. • Hardness - defined by how well a substance will resist scratching by another substance.

Cohesion in Liquids• Surface tension - the property

of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules.

• a principle that explains why fluids are often drawn up into other substances. This phenomenon is also sometimes described as “capillarity.” A classic example of this action involves a paper towel and a spilled puddle of water: when the towel is dipped into the water, it sucks the water up. It explains a large number of events that occur in nature, from how trees manage to get water all the way up to their crowns to the way in which water seems to climb up a straw.

Forms of Energy• Potential Energy is any type of stored

energy. It can be chemical, nuclear, gravitational or mechanical. 

• Kinetic Energy is energy in motion. An airplane flying or a meteor plummeting each have kinetic energy. Even the tiniest things have kinetic energy, like atoms vibrating when they are hot or when they transmit sound waves. Electricity is the kinetic energy of flowing electrons between atoms.

Energy – capacity to do work.• Potential Energy is any type

of stored energy. It can be chemical, nuclear, gravitational or mechanical.

• Kinetic Energy is found in movement. An airplane flying or a meteor plummeting each have kinetic energy. Even the tiniest things have kinetic energy, like atoms vibrating when they are hot or when they transmit sound waves energy of flowing electrons between atoms.