MATTER AND ENERGY CHAPTER TWO

Concepts Matter consists of elements and compounds, which in turn are made up of atoms, ions, or molecules Whenever matter undergoes a physical or chemical change, no atoms are created or destroyed (the law of conservation of matter)

What is matter? Three physical states: –Solid –Liquid –Gas Two chemical forms of matter: –Elements –Compounds

STATES OF MATTER

Other facts about matter: The smallest unit of matter is ___? What is an ion? What is a molecule and how are they held together? What are subscripts and what do they represent? The three physical states of matter on earth are____.

What is an element? A fundamental type of matter that has a unique set of properties and cannot be broken down into simpler substances by chemical means Periodic table: elements arranged based on their chemical behavior

The Atom Major parts of the atom are: –Protons –Neutrons –Electrons The protons and neutrons form the ___ Electrons are located in ____ What is the atomic number? What is the mass number? What are isotopes? How do you identify isotopes in the symbol?

ISOTOPES

WHAT ARE IONS? IF AN ATOM HAS 11 PROTONS AND 10 ELECTRONS IT IS A ______ION. IF IT HAS 17 PROTONS AND 18 ELECTRONS IT IS A ___ ION. HOW ARE THE CHARGES ON AN ION SHOWN AFTER THE SYMBOL?

Holding atoms together What does a chemical formula tell you? What are the characteristics of ionic bonds? What is an example of an ionic bond? What are covalent bonds? What is an example of a covalent bond? What are hydrogen bonds? What is an example of a hydrogen bond compound?

Covalent bonds

Other important compounds

Hydrogen bonds

What are organic compounds? What element do all organic compounds contain? What other elements can be also combined? Organic compounds can be natural or synthetic. Most organic compounds are covalent bonds.

Types of organic compounds: Hydrocarbons made up of ___ Chlorinated hydrocarbons –An example would be: Chlorofluorocarbons - –An example would be: Simple carbohydrates Monomers Polymers Complex carbohydrates Proteins Nucleic acids

MORE ON PROTEINS: ALPHA-AMINO ACIDS - 20 DIFFERENT MONOMERS - # & SEQUENCE SPECIFIED BY GENETIC CODE IN DNA MOLECULES IN CELLS NUCLEIC ACIDS - DNA & RNA - MADE BY LINKING MONOMERS CALLED NUCLEOTIDES TOGETHER

GENES - SEUQENCES OF NUCLEOTIDES - CARRIES A CODE WHICH CONTAINS TRAITS PASSED FROM PARENTS TO OFFSPRING GENOME - ALL OF THE GENETIC INFORMATION FOR AN ORGANISM. What are GENE MUTATIONS? What are CHROMOSOMES?

Some important elements Composition of the earth’s crust Inorganic compounds All compounds that do not contain carbon Crust - outermost layer of earth - mainly inorganic minerals and rocks

Matter quality A measure of how useful a matter resource is - based on availability and concentration High quality matter - organized, concentrated and usually found near earth’s surface Low quality - disorganized, dilute,often deep underground or dispersed in the ocean or atmosphere - have little potential use as a matter resource.

Matter Quality

WHAT IS ENERGY? What is ENERGY ? What is WORK? What is a FORCE? Forms of energy - light, heat, electricity, chemical energy, mechanical energy, and nuclear energy

Types of energy What is Kinetic energy? What does it depend on? Examples: wind, flowing water, electricity, electromagnetic radiation, heat, temperature What is Potential energy? What does it depend on? Potential energy changes into kinetic energy etc.

Electromagnetic spectrum Transverse waves Different wavelengths and frequencies Ionizing radiation - harmful forms of electromagnetic radiation Non-ionizing radiation - does not contain enough energy to form ions

Temperature What is temperature? –The average speed of the motion of the molecules in a given sample of matter What is heat? –The total kinetic energy of all the moving molecules within a given substance

How is heat transferred? What is convection? What is Conduction? What is Radiation?

Energy quality An energy source’s ability to do useful work High-quality - organized or concentrated - can perform useful work –Electricity, coal, gasoline, sunlight,uranium Low - quality - disorganized or dispersed- can perform little useful work –Heat in water, air, etc.

Changes in matter What is a Physical change? What are some examples of physical changes? All changes involve energy - taken in or released What is a Chemical change ? What is an example? What is a CHEMICAL Equation? Reactants --> products

Law of Conservation of Matter All the matter on earth is here and cannot be “thrown away” - there is no “away” Earth is a closed system Matter cannot be created nor destroyed Matter is not consumed

Nuclear changes Natural radioactivity- when nuclei of certain isotopes spontaneously break down into one or more different isotopes –Three types: –1. Natural radioactive decay –2. Nuclear fission –3. Nuclear fusion

Law of Conservation of matter and energy Applies to nuclear changes because a certain amount of mass (matter) is changed into energy. The TOTAL amount of matter and energy involved remains the same

What are Pollutants? Severity of their effects depends on: –Chemical nature –Concentration –Persistence Three categories: –Degradable – nonpersistent –Biodegradable –Slowly degradable - Presistent –Nondegradable

Nuclear Changes Changes in the nucleus of the atom Three types: –Natural radioactive decay –Nuclear fission –Nuclear fusion

Natural radioactive decay Unstable isotopes - radioisotopes - spontaneously break down and emit: Alpha particles - positively charged helium nuclei Beta particles - high speed electrons Gamma rays - high speed ionizing electromagnetic radiation

Half-life Rate of decay Time needed for one half of the nuclei in a radioisotope to decay and emit their radiation Eventually forms a new element Is not affected by temp. pressure, chemical changes, etc. Rule is store for 10 half-lives for safety

Nuclear fission Nuclei of atoms with large mass numbers are split into lighter nuclei Neutrons used to split Releases more neutrons and energy Critical mass - needed to start reaction

More on fission Atomic bombs - uncontrolled nuclear fission Damage cells Used in nuclear power plants

Nuclear fusion Two isotopes of light elements are combined under great heat and pressure to form a heavier nucleus Harder to initiate Thermonuclear weapons

Ionizing Radiation – from natural or background sources –Can come from space, soil, food, etc. –Has energy to knock electrons from atoms Can disrupt living cells, interfere with body processes and cause cancer. –Nonionizing radiation doesn not contain enough energy to form ions.

First law of thermodynamics In all physical and chemical changes, energy is neither created nor destroyed but it may be converted from one form to another Energy input always equals energy output You can’t get something for nothing - cannot get more energy out of a system than is put in!!!

Second law of thermodynamics When energy is changed from one form to another, some useful energy is always degraded to lower quality less useful energy usually heat lost to the environment We ALWAYS end up with less useful energy than we started with. An incandescent light bulb - 5 % light, 95% heat

More on 2nd law We can NEVER recycle or reuse high quality energy to do useful work. You get high quality matter and energy in your body, you use it and you add low quality waste matter and heat to the environment.

What is energy efficiency? A measure of how much useful work is accomplished by a particular input of energy into a system Always measured as a percent (%) Affects life because you get and use high quality matter and energy, use it and add low quality heat and waste back into the environment.