2Explanation of TermsChemistry – The study of matter and the changes it undergoes.Matter – Anything that has mass and takes up space (volume). Made up of atoms. Behavior explained by changes that atoms undergo.Mass – The amount of matter in an object. Always constant in all locations.
3Explanation of TermsWeight – Pull of gravity on an object. Changes with location. Since gravity on the moon is 1/6th that on earth, an object that weighs 60kg on earth will weigh 1/6 x 60kg on the moon, hence astronaut’s weightlessness on the moon.
4Explanation of TermsAll matter is made up of particles called atoms which are extremely small.The structure, composition, and behavior of all matter can be explained in terms of atoms and the changes they undergo.This is the study of chemistry.
5Things Not MatterSome things that are not matter – heat, light, radio waves.
6Fields of chemistryThere are so many types of matter, the study of matter is divided into five major fields or branches.
7Fields of chemistry Branch Area of emphasis Examples Organic chemistry Study of carboncompounds (there aresome exceptions)Medicines, plasticsInorganic chemistryStudy of all compounds not containing carbonMinerals, metals, semiconductorsPhysical chemistryStudy of behavior and changes of matter as well as the energy changesRates of reaction, mechanismsAnalytical chemistryStudy of components and composition of matterFood nutrients, food qualityBiochemistryStudy of matter and the processes in living thingsMetabolism, fermentation
8Scientific MethodAll scientists do investigations using a systematic approach.
10Scientific Method It involves the following steps: Making observations.Forming a hypothesis after gatheringinformation.Designing and performing an experiment to test the hypothesis. Observations are made and data collected.Analyzing the data from the experiments.Making conclusions from results of the experiment (data). Results may or may not agree with hypothesis. A lot can be learned from a negative result.
11Scientific MethodAfter a lot of experiments on a particular problem, a verbal or mathematical explanation, called a model, can be made.When such explanations have been tested and tested, a theory is formulated.
12Scientific MethodTheories that have remained the same after many experiments to test over a long period of time becomes a scientific law.
13Experiment What is an experiment? A set of controlled observations that test a hypothesis.One variable at a time is changed.
14ExperimentVariable – Quantity that can have more than one value, ex: temperature.Independent variable – Variable that is manipulated (changed) by the scientist, ex: volume of water.Dependent variable – Variable that responds to the independent variable, ex: masses of different volumes of water.
15ExperimentMany experiments include a control which is a standard reference for comparison. This could be a sample that does not include the variable being tested.
16Research There are two types of research: Pure research – Done mainly for knowledge, ex: behavior of CFCs.Applied research – Done to solve a specific problem, ex: finding chemicals to replace CFCs because they deplete ozone, finding cure for AIDS, or Diabetes.Application of scientific knowledge to improve life, comfort.
17Safety Safety: This is priority #1 in chemistry. You are responsible for your safety and that of all your classmates. Safety in a chemical lab is like driving safety.Refer to page 19 of your textbook and the Safety in the Laboratory handout.Remember the safety tips from the safety video.