Unit 1. Matter and Change

Do Now:

What are the State of Matter?

Objectives:

Define the term “chemistry”

Describe the difference branches of Chemistry.

Describe the difference between a physical change and a chemical change and give several examples of each.

Describe different characteristics of the three states matter.

Classify a mixture as homogeneous or heterogeneous.

Classify a pure substance as an element or a compound.

Chapter 1Section 1

Chemistry is a Physical Science

Chemistry is the study of matter and the changes that it undergoes.

Biological Science

Physical Sciences

Chemistry

Chemistry is central to all sciences.

Both living and non living matter have a chemical structure.

Chemistry deals with: 1. What is material made of?

2. What is the makeup and internal arrangement of the atoms?

3. How does it behave when heated, cooled or mixed with other materials?

Branches of Chemistry

Organic chemistry – the study of carbon containing compounds.

Inorganic chemistry – the study of substances that do not contain carbon (metals and gases).

Physical chemistry – the study of the properties and changes of matter and their relation to energy.

Analytical chemistry –the identification of the components and composition of materials.

Biochemistry – the study of the processes occurring in living systems.

Types of Research

Basic Research - carried out for the sake of increasing knowledge.

Most basic research is carried out in universities.

Research is normally published in scientific journals.

Types of Research

Applied Research - carried out to solve a problem.

Research is carried out by companies to make a profit.

Usually short term goals set by the company.

Summary

1) Define the word chemistry.

2) Name the five branches of chemistry.

3) Define basic and applied research.

STATE OF MATTER

States of Matter There are Four state of matter A. Solid B. Liquid C. Gas D. Plasma

State of matter depends on Kinetic Energy between the particles

A. Kinetic Molecular Theory

KMT

Particles of matter are always in motion.

The kinetic energy (speed) of these particles increases as temperature increases.

Four States of Matter

A. Solidsvery low KE - particles

vibrate but can’t move around

fixed shape fixed volume

Four States of Matter

B. Liquids low KE - particles can

move around but are still close together

variable shapefixed volume

Four States of MatterC. Gases

high KE - particles can separate and move throughout container

variable shapevariable volume

Matter and its Properties It’s Classified!

Objective Distinguish between:

intensive and extensive properties Physical & chemical changes/properties Classify matter

Properties & Changes in Matter

Extensive vs. Intensive

Physical vs. Chemical

A. Extensive vs. Intensive Extensive Property

depends on the amount of matter present

ex,.-

Intensive Property depends on the identity of substance, not

the amount

Ex.-

A. Extensive vs. Intensive Extensive Property

depends on the amount of matter present

ex,.- Volume, mass, Energy

Intensive Property depends on the identity of substance, not the

amount

Ex.- melting point, boiling point, conduct electricity or heat

WHAT ABOUT DENSITY??

A. Extensive vs. Intensive Examples:

boiling point

volume

mass

density

conductivity

A. Extensive vs. Intensive Examples:

boiling point…… intensive

Volume …. extensive

Mass ….. extensive

Density ….. intensive

Conductivity ….. intensive

PROPERTYB. Physical vs. Chemical Physical Property

can be observed without changing the identity of the substance

Chemical Property describes the ability of a substance to

undergo changes in identity

B. Physical vs. ChemicalExamples:

melting point

flammable

density

magnetic

tarnishes in

air

physical

chemical

physical

physical

chemical

B. Physical vs. ChemicalExamples:

melting point

flammable

density

magnetic

tarnishes in

air

physical

chemical

physical

physical

chemical

CHANGEC. Physical vs. Chemical Physical Change

changes the form of a substance without changing its identity

properties remain the same

Chemical Change changes the identity of a substance products have different properties

B. Physical vs. Chemical Signs of a Chemical Change

change in color or odor

formation of a gas

formation of a precipitate (solid)

change in light or heat

In the example of burning of charcoal, carbon and oxygen are the reactants in the combustion reaction. Carbon dioxide is the product.

carbon + oxygen carbon dioxide

C + O2 CO2

(reactants) (product)

Properties and Changes in Matter

B. Physical vs. Chemical Examples:

rusting iron

dissolving in water

burning a log

melting ice

grinding spices

B. Physical vs. Chemical Examples:

rusting iron

dissolving in water

burning a log or

charcoal

melting ice

grinding spices

chemical

physical

chemical

physical

physical

Four States of MatterD. Plasma

very high KE - particles collide with enough energy to break into charged particles (+/-)

gas-like, variableshape & volume

stars, fluorescentlight bulbs, CRTs

SOLUTIONS AND

MIXTURES

Objective: Classification of Matter

DO NOW: What is a solution? Describe the difference between a

heterogeneous and homogenous mixture

A. Pure Substances Element

composed of identical atoms EX: copper wire, aluminum foil

A. Pure Substances

Compound composed of 2 or more elements

in a fixed ratio

properties differ from those of individual elements

EX: table salt (NaCl)

A. Pure Substances Law of Definite Composition

A given compound always contains the same, fixed ratio of elements.

Law of Multiple Proportions Elements can combine in different ratios to form

different compounds.

A. Pure Substances For example…

Two different compounds, each has a definite composition.

Pure Substances(constant composition)

Elements Listed on the Periodic

Table Cannot be broken down

into unique components Na, Cl, Al, O2, S8

Compounds Made of elements that

are chemically joined Can be broken down NaCl, H2O, AlCl3, H2SO4

B. Mixtures Variable combination of 2 or more pure substances.

Heterogeneous Homogeneous

B. Mixtures(variable composition)

Homogeneous – Solutions evenly distributed

Heterogeneous not evenly distributed

B. Mixtures

Solutionhomogeneousvery small particlesno Tyndall effect

Tyndall Effect

B. MixturesColloid

heterogeneousmedium-sized particlesTyndall effectparticles don’t settleEX: milk

B. MixturesSuspension

heterogeneous large particlesTyndall effectparticles settleEX: fresh-squeezed

lemonade

C. Mixtures Examples:

mayonnaise

muddy water

fog

saltwaterItalian salad dressing

C. Mixtures Examples:

mayonnaise

muddy water

fog

saltwaterItalian salad dressing

colloid

suspension

colloid

solution

suspension

A. Matter Flowchart

MATTER

Can it be physically separated?

Homogeneous Mixture(solution)

Heterogeneous Mixture Compound Element

MIXTURE PURE SUBSTANCE

yes no

Can it be chemically decomposed?

noyesIs the composition

uniform?

noyes

Colloids Suspensions

A. Matter Flowchart Examples:

graphite

pepper

sugar

(sucrose)

paint

soda

A. Matter Flowchart Examples:

graphite

pepper

sugar

(sucrose)

paint

soda

element

hetero. mixture

compound

hetero. mixture

solution

Tea – Homogeneous Mixture

Air – Homogeneous Mixture

Alloys – Homogeneous Mixtures

Cereal – Heterogeneous Mixture

Sand – Heterogeneous Mixture

Separating Mixtures Only a physical change- no new matter Filtration - separate solids from liquids

with a barrier (filter paper) Distillation - separate liquids because of

different boiling points Heat mixture Catch vapor in cooled area

Chromatography - different substances are attracted to paper or gel, so move at different speeds

The Periodic Table

A. Mendeleev

Dmitri Mendeleev (1869, Russian) Organized elements

by increasing atomic mass.

Elements with similar properties were grouped together.

There were some discrepancies.

C. Johannesson

A. Mendeleev Dmitri Mendeleev (1869, Russian)

Predicted properties of undiscovered elements.

C. Johannesson

B. Moseley Henry Moseley (1913, British)

Organized elements by increasing atomic number.

Resolved discrepancies in Mendeleev’s arrangement.

C. Johannesson

II. Organization of theElements

A. Metallic CharacterMetalsNonmetalsMetalloids

C. Johannesson

B. BlocksMain Group

ElementsTransition MetalsInner Transition

Metals

C. Johannesson

Do Now: Classify the following as either a METAL, NON-METAL or METALLOID:

a. Aub. Sic. Brd. An element that is brittle and conducts

electricitye. An element that is malleablef. An element that has tendency to become an

anion

Periods and Families Periods: horizontal rows on the periodic

table physical and chemical properties change

somewhat regularly across a row. Elements closer to each other in the same

period tend to be similar than those that are farther apart.

Families: vertical rows of elements, aka groups Each group contains similar chemical

properties

Types of ElementsMETALS:

Shiny

Conductors of heat and electricity

Most metals are malleable (can be pounded into thin sheets; a sugar cube sized chunk of gold can be pounded into a thin sheet which will cover a football field),

Most metals are ductile (can be drawn out into a thin wire).

Metals cont…..

All are solids at room temp (except Mercury, which is a liquid)

Metals tend to have low ionization energies, and typically lose electrons (i.e. are oxidized) when they undergo chemical reactions

Alkali metals are always 1+ (lose the electron in s subshell)

Alkaline earth metals are always 2+ (lose both electrons in s subshell)

Compounds of metals with non-metals tend to be ionic in nature.

Types of ElementsNON- METALS:

Vary greatly in appearance Non-lustrous Poor conductors of heat and electricity The melting points of non-metals are

generally lower than metals Seven non-metals exist under standard

conditions as diatomic molecules: H2(g) N2(g) O2(g) F2(g) Cl2(g) Br2(l) I2(l) (volatile liquid - evaporates readily)

Non-Metals cont…….. Nonmetals, when reacting with metals,

tend to gain electrons (typically attaining noble gas electron configuration) and become anions: Nonmetal + Metal -> Salt

Compounds composed entirely of nonmetals are molecular substances (not ionic)

Types of Elements

Metalloids:

Elements may share properties of metals and non-metals.

A stair-step line separates the metals from the nonmetals on the periodic table.

Metalloids cont…… Properties: All metalloids are solids at room temperature.

Less malleable than metals but not as brittle as nonmetals.

Metalloids tend to be semiconductors of electricity. (intermediate between metals and nonmetals).

Metalloids cont……

Properties:

Metalloids are used in semiconducting materials found in computers, calculators, televisions and radios.

Elements include: boron, silicon, germanium, antimony

Noble Gases Noble Gases - the elements in Group

18 of the periodic table. They are considered nonmetals. These elements are generally

unreactive. All are gases at room temperature. Examples: neon, argon, krypton,

xenon (all used in lighting) and helium.