chemphys unit 1: matter

Chemistry & Physics

UNIT 1: MATTER

Some rules

• Listen when others are talking

• Show respect for other opinions

• If you don’t understand, don’t hesitate to ask (raise hand)

• No cellphones in the class room

• Full participation is asked

Chemistry

Matter

Atoms

Periodic table

Chemical bonding

Chemical reaction

Electrolytes

Hydrocarbons

Organic chemistry

Physics

GasesLiquids

Solutions

Energy

HeatForce & Motion

Light & Vision

Sound & Hearing

Electricity

Course content

• Theory– Chemistry for the Health Sciences – G.I. Sackheim & D.D. Lehman– Applied Science for Nurses– I.M. Hofmeyr

• Practice: demonstrations in laboratory science– Chemical reactions– Physical processes

• Tests• Assignments• Final examination

Website

• http://pson-biochemphys.yurls.net/en/page/

Today

• Chemistry versus Physics– Chemical and physical change

• Matter– Mass and weight– Units– Conservation of mass

• States of matter– Solid, liquid, gas– Change of state– Properties

• Composition of matter– Elements, compounds, mixtures

Chemistry vs Physics

CHEMICAL REACTIONS

PHYSICAL PROCESSES

Chemical & physical change

• CHEMISTRY– Change:

“Formation of new substances”“Making/breaking atomic bonds”

– Chemical reactions

• CHEMISTRY PHYSICS– Boiling water in a pan

• Physics: water becomes gas, but molecules are still the same– Burning glucose in your body

• Chemistry: water and carbon dioxide are formed– Milk became sour

• Chemistry: sour-tasting lactic acid is formed– Dissolving sugar in hot tea

• Physics: sugar molecules dispersed in water, but molecules are still the same

• PHYSICS– Change:

“No new substances”“Rearrangement of molecules”

– Physical processes

What is matter

• Topic of today: MATTER– Anything that occupies space– With a specific mass (weight)

Matter that we CANNOT see or feel

Matter that we CAN see or feel

Sackheim’s Chemistry: Chapter 2

Mass vs Weight

• Daily life: Mass is referred to as Weight • Science: Mass is not the same as Weight

– Mass = amount of matter in an object• Constant

– Weight = force experienced by an object due to gravity(depends on pull of gravity)

• Varies per “location”


Units

• SI system– To measure quantities– International system for units

• Fundamental units– Length: meter (m)– Mass: kilogram (kg)

• Or gram (1000 g = 1 kg)– Time: seconds (s)

• Not minutes, hours, days– Temperature: Kelvin (K)

• Absolute zero, “brrrrrrrrr”• Not degrees Celcius (K = °C + 273)

• Derived units– Volume: m3

• Or liter (1 m3 = 1000 L)• Derived from length

• Units in medicine– Length: meter (m)– Mass: gram (g)– Volume: liter (L)


Prefixes

Prefix Abbreviation Decimal Expression

Exponential Expression

mega M 1.000.000 106

kilo k 1.000 103

hekto h 100 102

deka da 10 101

- - 1 100

deci d 0.1 10-1

centi c 0.01 10-2

milli m 0.001 10-3

micro μ (or mc) 0.000001 10-6

nano n 0.000000001 10-9


Conversions

• Mass– 1 g = 10 dg = 100 cg = 1000 mg– 1 kg = 1000 g

• Length– 1 m = 10 dm = 100 cm = 1000 mm– 1 kg = 1000 m

• Volume– 1 L = 10 dL = 100 cL = 1000 mL – 1 kL = 1000 L = 1 m3


Conservation of mass

• Ancient Greek philosophy (500 BC)– “Nothing comes from nothing”– Early statement referring to…

• …Law of conservation of mass (1774)– “During chemical reaction mass is neither created nor destroyed”– Mass before reaction (reactants) = Mass after reaction (products)

Antoine LavoisierSackheim’s Chemistry: Chapter 2

States of matter

SOLID

LIQUID

GAS

Solid

• Piece of gold = solid– Definite shape

• Cannot be changed easily– Definite volume

• Cannot be changed easily– Particles are tightly packed (motion is restricted)


No flow

Liquid

• Pint of beer = liquid– No definite shape

• Can be poured from one glass to the other• Beer assumes shape of new glass

– Definite volume• Volume of beer remains the same regardless of glass

– Particles close together (motion is less restricted)

Flow


Gas

• When finished… empty bottle of beer filled with air = gas– No definite shape

• Gas can be transfered from one bottle to another– No definite volume

• More air can be forced in bottle– Particles are far from apart (motion is unrestricted)

• Low densitySackheim’s Chemistry: Chapter 2

Solid, gas, liquid

• Definite shape• Definite volume• Particles tightly packed• No flow possibe• Incompressible• Expand slightly if heated

• No definite shape• Definite volume• Particle close together• Flow possible• Incompressible• Expand slightly if heated

• No definite shape• No definite volume• Particle far apart (low density)

• Compressible• Expand greatly if heated


Changes of state


Physical changes

• All about change in motion of particles– Melting/freezing– Evaporation/condensation– Sublimation

• T-t diagram– Phase changes

• Constant temperature

• Change the state: chemistry of physics?

Properties

• Distinguish materials: Properties – Identification– Sugar versus salt?

• Physical properties– Tells what a substance is– e.g. color, odor, taste, solubility, density, hardness, melting point

• Chemical properties– Tells what a substance does– e.g. reacting in air, reacting in acid, burning in flame


Composition of matter

ELEMENTS

COMPOUNDS

MIXTURES

PURE SUBSTANCES

Elements

• Building blocks of matter: Elements– “cannot be broken down into any simpler substance”– Classification in two groups…

• Classification– Metals

• Conduct heat/electricity• Shiny surface, reflect light• High tensile strength• Easily processable• Solid or liquid at RT

• Elements identified by Symbols– Abbreviation of English name– Abbreviation of Latin name


– Nonmetals• Do not conduct heat/electricity very well• Not shiny, seldom reflect light• Frequently brittle• Not processable• Solid, liquid or gaseous at RT

Elements of human life (1)

Element Symbol Function

Oxygen O Required for water and organic compounds

Carbon C Required for organic compounds

Hydrogen H Required for water and organic compounds

Nitrogen N Required for organic compounds, proteins

Sulfur S Required for organic compounds, proteins

Calcium Ca Required for bones, teeth, necessary for enzymes, nerve musle functions, hormonal action, cellular motility, clotting of blood

Phosphorus P Required for bones, teeth, necessary for high-energy compounds, proteins, DNA/RNA, phospholipids

Magnesium Mg Required for many enzymes, necessary for energy reactions

Sodium Na Positive extracellular ion

Potassium K Positive intracellular ion

Chlorine Cl Negative ions


Elements for human life (2)

Element Symbol Function

Iodine I Required for hormones

Fluorine F Required for bones, teeth, inhitor of enzymes

Iron Fe Required for hemoglobin, enzymes

Copper Cu Required for enzymes, hemoglobin, bone formation

Zinc Zn Required for enzymes, related to action of insulin, essential to growth and reproduction, nucleic acid metabolism

Manganese Mn Required for enzymes, essential to bone structure, reproduction, central nervous system

Cobalt Co Required for vitamin B12

Molybdenum Mo Required for enzymes, essential to purine metabolism

Chromium Cr Related to action of insulin

Selenium Se Essential for action of vitamin E


Compounds

• Build from elements: Compounds– “can be broken down into simpler substances by chemical means”

• Characteristics– Can be separated– Homogeneous

(every piece is the same)– Different properties compared

to substances from which theyoriginate

• Example: Water (H20)– Decomposes into hydrogen and oxygen– All water drops have same properties– Water has different properties

compared to hydrogen and oxygen


WaterWhat else?

Law of definite proportions

• Consider a pile of sugar– Sugar contains carbon, hydrogen and oxygen

– Two samples: both contain exact same percentage of C, H and O– This is in example of the law of definite proportions:

”Compounds are composed of fixed ratio of elements as determined by mass”– Sugar: Always 40% C, 7% H, 53% O

Sample 1:- Heat teaspoon of sugar until only carbon is left- Amount of carbon?

Sample 2:- Heat teaspoon of sugar until only carbon is left- Amount of carbon?


Mixtures

• Combination of substances: Mixture– Either a combination of elements or compounds

• Characteristics (upcoming experiment)– No definite proportion / composition (unlike compounds)– Separated into their components by physical means– Components retain their individual properties

• Composition– Homogeneous

• Mixture of water and sugar: the same composition throughout

• Sugar cannot be distinguised anymore from the water

– Heterogeneous• Mixture of sugar and sand:

different composition throughout• One solid can be distinguished

from another


Separation of mixtures

EXPERIMENT 001Title: Sugar with SandTopic: Separation by physical means

1. Composition is variable– Add more water or sand

2. How to separate?– Physical processes:

evaporation, filtering

3. Sugar and sand retain properties

Summary (1)

Matter

Pure substance

Elements

Metals Nonmetals

Compounds

Mixtures

Homogenous Heterogenous

Summary (2)

The End

Test your memory

A. True or False1. Physical change is about the formation of new substances2. Weight is the force experienced by an object due to gravity3. Liquids have a definite shape and no definite volume4. During a change of state, the temperature rises5. Nitrogen and sulfur are important sources for body proteins

B. Multiple choice1. Which of the following is a heterogenous mixture

a) The pacific ocean; b) Wine; c) Blood plasma

2. Which substance is not a compounda) Alcohol; b) Beer; c) Water

3. Antoine Lavoisier stateda) The law of definite proportions; b) The law of conservation of energy; c) The law of conservation of mass

chemphys unit 1: matter

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