Welcome to the World of Chemistry

The Language of Chemistry CHEMICAL ELEMENTS -CHEMICAL ELEMENTS - –pure substances that cannot be decomposed by ordinary means to other substances. Sodium Bromine Aluminum

The Language of Chemistry The elements, their names, and symbols are given on the PERIODIC TABLEThe elements, their names, and symbols are given on the PERIODIC TABLE How many elements are there?How many elements are there?

The Periodic Table Dmitri Mendeleev ( )

Glenn Seaborg ( ) Discovered 8 new elements.Discovered 8 new elements. Only living person for whom an element was named.Only living person for whom an element was named.

Branches of Chemistry Many major areas of study for specializationMany major areas of study for specialization Several career opportunitiesSeveral career opportunities Also used in many other jobsAlso used in many other jobs

1. Organic Chemistry Organic is the study of matter that contains carbonOrganic is the study of matter that contains carbon Organic chemists study the structure, function, synthesis, and identity of carbon compoundsOrganic chemists study the structure, function, synthesis, and identity of carbon compounds Useful in petroleum industry, pharmaceuticals, polymersUseful in petroleum industry, pharmaceuticals, polymers

2. Inorganic Chemistry Inorganic is the study of matter that does NOT contain carbonInorganic is the study of matter that does NOT contain carbon Inorganic chemists study the structure, function, synthesis, and identity of non- carbon compoundsInorganic chemists study the structure, function, synthesis, and identity of non- carbon compounds Polymers, MetallurgyPolymers, Metallurgy

3. Biochemistry Biochemistry is the study of chemistry in living thingsBiochemistry is the study of chemistry in living things Cross between biology and chemistryCross between biology and chemistry Pharmaceuticals and geneticsPharmaceuticals and genetics

4. Physical Chemistry Physical chemistry is the physics of chemistry… the forces of matterPhysical chemistry is the physics of chemistry… the forces of matter Much of p-chem is computationalMuch of p-chem is computational Develop theoretical ideas for new compoundsDevelop theoretical ideas for new compounds HONK if you passed p-chem

5. Analytical Chemistry Analytical chemistry is the study of high precision measurementAnalytical chemistry is the study of high precision measurement Find composition and identity of chemicalsFind composition and identity of chemicals Forensics, quality control, medical testsForensics, quality control, medical tests

THE SCIENTIFIC METHOD 1. THINK OF AN IDEA OR PROBLEM 2. RESEARCH 3. PLAN AN EXPERIMENT 4. EXPERIMENT 5. COLLECT DATA 6. DRAW CONCLUSIONS

What is a hypothesis?

Types of Observations and Measurements We make QUALITATIVE observations of reactions — changes in color and physical state.We make QUALITATIVE observations of reactions — changes in color and physical state. We also make QUANTITATIVE MEASUREMENTS, which involve numbers.We also make QUANTITATIVE MEASUREMENTS, which involve numbers. –Use SI units — based on the metric system

EXPERIMENTS CONTAIN: Independent variables: Is changed by regular intervals. Dependent variable: measured against independent variable Control: Used to show whether the measured factor has any effect.

Determine the independent and dependent variables, hypothesis, and control in the following: A student thought that watering plants with an iron solution and then placing magnets over them would cause them to grow faster. She watered one set with the iron solution and one with plain water. Both sets of plants had magnets hung over them. The height of the plants was measured once a week.

Pure ResearchApplied Research

SI measurement Le Système international / International System / MetricsLe Système international / International System / Metrics The only countries that have not officially adopted SI are Liberia (in western Africa) and Myanmar (a.k.a. Burma, in SE Asia), but now these are reportedly using metric regularlyThe only countries that have not officially adopted SI are Liberia (in western Africa) and Myanmar (a.k.a. Burma, in SE Asia), but now these are reportedly using metric regularly Metrication is a process that does not happen all at once, but is rather a process that happens over time.Metrication is a process that does not happen all at once, but is rather a process that happens over time. Among countries with non- metric usage, the U.S. is the only country significantly holding out.The U.S. officially adopted SI in 1866.Among countries with non- metric usage, the U.S. is the only country significantly holding out. The U.S. officially adopted SI in Information from U.S. Metric Association

Standards of Measurement When we measure, we use a measuring tool to compare some dimension of an object to a standard. For example, at one time the standard for length was the king’s foot. What are some problems with this standard?

Stating a Measurement In every measurement there is a  Number followed by a  Unit from a measuring device The number should also be as precise as the measurement!

UNITS OF MEASUREMENT Use SI units — based on the metric system LengthMassVolumeTimeTemperature Meter, m Kilogram, kg Seconds, s Celsius degrees, ˚C kelvins, K Liter, L

Mass vs. Weight Mass: Amount of Matter (grams, measured with a BALANCE)Mass: Amount of Matter (grams, measured with a BALANCE) Weight: Force exerted by the mass, only present with gravity (pounds, measured with a SCALE)Weight: Force exerted by the mass, only present with gravity (pounds, measured with a SCALE) Can you hear me now?

Some Tools for Measurement Which tool(s) would you use to measure: A. temperature B. volume C. time D. weight

Solution A. temperaturethermometer B. volume measuring cup, graduated cylinder C. timewatch D. weightscale

Learning Check Match L) length M) mass V) volume ____ A. A bag of tomatoes is 4.6 kg. ____ B. A person is 2.0 m tall. ____ C. A medication contains 0.50 g Aspirin. ____ D. A bottle contains 1.5 L of water.

Learning Check What are some U.S. units that are used to measure each of the following? A. length B. volume C. weight D. temperature

Metric Prefixes Kilo- means 1000 of that unitKilo- means 1000 of that unit –1 kilometer (km) = 1000 meters (m) Centi- means 1/100 of that unitCenti- means 1/100 of that unit –1 meter (m) = 100 centimeters (cm) –1 dollar = 100 cents Milli- means 1/1000 of that unitMilli- means 1/1000 of that unit –1 Liter (L) = 1000 milliliters (mL)

Metric Prefixes

Units of Length ? kilometer (km) = 500 meters (m)? kilometer (km) = 500 meters (m) 2.5 meter (m) = ? centimeters (cm)2.5 meter (m) = ? centimeters (cm) 1 centimeter (cm) = ? millimeter (mm)1 centimeter (cm) = ? millimeter (mm) 1 nanometer (nm) = 1.0 x meter1 nanometer (nm) = 1.0 x meter O—H distance = 9.4 x m 9.4 x cm nm O—H distance = 9.4 x m 9.4 x cm nm

Learning Check Select the unit you would use to measure 1. Your height a) millimeters b) meters c) kilometers 2. Your mass a) milligramsb) grams c) kilograms 3. The distance between two cities a) millimetersb) meters c) kilometers 4. The width of an artery a) millimetersb) meters c) kilometers

Equalities State the same measurement in two different units length 10.0 in cm

m = 1 ___a) mm b) km c) dm g = 1 ___ a) mg b) kg c) dg L = 1 ___a) mL b) cL c) dL m = 1 ___ a) mm b) cm c) dm Learning Check