Chem Ch. 2 (Matter)

physical properties

A characteristic of a pure substance that can be observed without changing it into another substance

electromagnetic energy

A form of energy that travels through space as waves

Differentiate between physical and chemical properties of matter. give two examples of each property

A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include color, density, hardness, and melting and boiling points. A chemical property describes the ability of a substance to undergo a specific chemical change. Chemical properties include flammability, toxicity, and chemical stability.

element

A pure substance made of only one kind of atom

endothermic

Absorbs heat/energy

Compare and contrast gases and plasmas.

Both gases and plasmas consist of energetic particles that are so far apart that attractive forces between particles are inconsequential. both highly compressible, have no definite volume, and can diffuse to occupy a volume of space. gases consist of intact atoms or molecules, while the particle in plasmas are mostly ions and free electrons. The temperature of plasmas are usually several orders of magnitude higher than that of gases.

chemical properties

Characteristics of a substance that determine how it will react with other substances.

thermal energy

Heat energy; is the sum of the kinetic energies of all particles in the system.

Explain the differences between heterogeneous and homogeneous mixtures.

Heterogeneous mixtures are not mixed all the way, and have a distinguishable separation. Homogenous mixtures are the same all the way throughout, or fully mixed.

Third Law of Thermodynamics

No system can reach absolute zero

chemical subscripts

Numbers written at the lower right of a chemical symbol

physical changes at the particle level

The positions or motions of the particles may change; chemical bonds between particles remain unchanged

Thermodynamics

The study of energy transformations that occur in a collection of matter.

explain the difference between temperature and thermal energy

The thermal energy, or heat, of an object is obtained by adding up the kinetic energy of all the molecules within it. Temperature is the average kinetic energy of the molecules

mixture

a material that can be separated by physical means into two or more substances

absolute zero

a temperature of 0 kelvins; the temp at which there is no longer any molecular or atomic movement

Convert the following temperature from the Kelvin to the Celsius Scales. a. 496 K (temperature of rock at 5.9 km depth) b. 2.726 K (average temperature of deep space) c. 1783 K (melting point of steel) d. 273.16 K (triple point of water)

a. 223 °C b. -270.42 °C c. 1510 °C d. 0.01 °C

Convert the following temperatures from Celsius to Kelvin scales. Express your answers to the nearest hundredth of a degree a. 0.00 °C (freezing point of water) b. 22.22 °C (room temperature) c. 100.00 °C (boiling point of water) d. -218.30 °C (melting point of oxygen)

a. 273.15 K b. 295.37 K c. 373.15 K d. 54.85 K

name the principle type of energy involved in each of the following; a. vibrations from a loudspeaker b. a pot of near boiling water c. a camera flash d. the source of explosion of dynamite e. changes occuring at the center of a star f. a rolling ball

a. acoustic b. potential c. electrical d. thermal e. nuclear f. kinetic

For each of the following elements, give the term that best describes how its atoms exist under "normal" conditions. Be as specific as possible. For example, N2 would be a diatomic element. a. oxygen (O2) b. red phosphorus (P4) c. sulfur (S8) d. helium (He)

a. diatomic element b. polyatomic element c. polyatomic element d. monatomic element

Give the number of each kind of atom in the following formula units or molecules. a. 5NaCl b. Ca(OH)2 c. HC2H3O2 d. 4Li2O

a. five Na, five Cl b. one Ca, two O, two H c. four H, two C, two O d. eight Li, four O

Name the changes of state that are described by the following processes. a. Pond water solidifies on a cold winter day. b. The fragrance of an open perfume bottle is smelled from across the room. c. Water leaves a teakettle that is sitting on a hot stove. d. Frost patterns appear on a cold window pane in winter. e. Water mist collects on the bathroom mirror after a shower. f. You smell the odor of moth balls when you open a clothes box. g. As a candle burns, wax drips down the sides of the candle.

a. freezing b. vaporization c. vaporization d. deposition e. condensation f. sublimation g. melting

second law of thermodynamics

all natural processes tend toward the highest entropy and minimum usable energy

atom

an individual unit of a pure substance (element)

heterogeneous

appears to consist of two materials segregated into distinct regions

Kinetic Molecular Theory

based on the idea that particles of matter are always in motion

Is energy something a system does or something it has?

energy is something a system has. the energy of a system consists of the motion of their individual particles and the motion of the system as a whole.

kinetic energy

energy of motion

mechanical energy

energy posessed by an object that is moving or has the potential to move

depostion

gas to solid

examples of physical change

ice melting, wheat being ground into flour, sugar dissolving

formula units

ionic compounds

law of conservation of mass-energy (first law of thermodynamics)

mass and energy cannot be created or destroyed, only converted from one form to another

what is matter, and where did it come from?

matter is anything that occupies space. it was created out of nothing by God

six most common forms of energy

mechanical, thermal, acoustic, electromagnetic, chemical, and nuclear

examples of chemical change

metal rusting, oil burning, wood rotting, food digesting

Robert Brown

named the nucleus; observed movement in matter (brownian motion)

observable chemical changes

new substances are formed that have different chemical and physical properties

coefficient

number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction

chemical symbol

one or two letters that represent an element

sublimation

solid to gas

potential energy

stored energy

Discuss why temperature is the most important factor in determining the state of a substance.

temperature can change the state of a substance very easily. one of the most important factors

Malleability

the ability of a substance to be hammered or beaten into thin sheets

energy

the ability to do work

density

the amount of mass in a given volume

naturalism

the belief that all observations can be explained on the basis of natural cause-and-effect relationships. leaves no room for the supernatural

entropy

the measure of the dispersal of energy

chemical changes at the particle level

the positions and chemical bonds of the particles change

homegeneous

the same throughout

internal energy

the sum of the kinetic and potential energies of all particles in the system

chemical formulas

way of describing elements and number of atoms that make up one molecule of a compound; uses symbols, subscripts and coefficients

suspension

when a heterogeneous mixture consists of groups of solid particles suspended in a liquid or gaseous phase

Sound (Acoustic) Energy

energy caused by the vibrations of an object

monatomic element

An element that occurs naturally as individual atoms

physical changes

Any change that DOES NOT alter the chemical composition of a substance.

matter

Anything that has mass and takes up space

State three evidences that the particles of substance are in continuous motion.

Diffusion of perfume odors in air, evaporation of steam droplets in air, and Brownian motion in microscopic objects.

chemical energy

Energy stored in chemical bonds

nuclear energy

Energy stored in the nucleus of an atom

condensation

Gas to liquid

molecules

Groups of two or more atoms held together by chemical bonds

Since heat transfers only take place between systems with different temperatures, explain why the third law of thermodynamics is support by our current understanding of matter.

In order to cool a point to absolute zero, the thermal energy in the particles at that point would have to flow to a colder spot, which is impossible, since there is no point colder than absolute zero by definition.

vaporization

Liquid to gas

What is a physical change? Give three examples of physical change.

Physical change is anything that changes a physical property of matter. Some examples are ice melting, sugar dissolving in water, and wood being cut.

What are the two main classes of matter, and what characteristics differentiate them?

Pure substances and mixtures. We can differentiate between the two based on physical and chemical properties of matter.

compounds

Pure substances that consist of two or more elements.

List the known states of matter in order form the most energetic to the least.

Quark-gluon plasma, plasma, gas, liquid, solid, Bose-Einstein condensate.

exothermic

Releases heat/energy

observable physical changes

Shape, state, size

(T or F) Liquids flow only when a force acts on them.

T

T or F, Molecules consisting of two or more elements are the smallest indentifiable particles of nonchrystalline compounds.

T

State the first law of thermodynamics. What does this law imply for the origins of matter and energy?

The First Law of Thermodynamics states that heat is a form of energy, and thermodynamic processes are therefore subject to the principle of conservation of energy. It implies that it energy has existed since the beginning of time.

conductivity

The ability of an object to transfer heat or electricity to another object.

Ductility

The ability to be pulled into thin wires

electrical energy

The energy of electric charges

Compare the entropy of a firecracker before it is lighted to its entropy after it explodes. Explain the difference.

The firecracker's entropy after it has burst is greater than before it is lighted. The firecracker has less usable energy and its parts are more disorganized (less ordered) after it explodes.

What specifically does thermodynamics investigate? What invention spurred in its development?

Thermodynamics is the study of the movement and conversion of energy. The steam engine.

chemical changes

changes that alter the composition of matter

ion

charged particle consisting of a single atom or group of atoms bonded together that has a net electrical charge

pure substance

consists of only one type of matter

polytomic elements

elements that naturally bond in three or more atom units

diatomic elements

elements that naturally bond into two atom units