Introduction to Chemistry Chemistry is the study of the composition of matter and the changes that matter undergoes. Matter is anything that has mass and occupies space. Most things in our world are matter

Introduction to Chemistry What isn’t matter?

Introduction to Chemistry What is wrong with an advertisement for juice drinks that claims the juice is all-natural and free of chemicals?

Introduction to Chemistry Chemistry has 5 areas of study Organic chemistry Organic chemistry is defined as the study of all chemicals containing carbon. Inorganic chemistry The study of chemicals that, in general, do not contain carbon is called inorganic chemistry. Biochemistry The study of processes that take place in living organisms is biochemistry. analytical chemistry The area of study that focuses on the composition of matter is analytical chemistry. physical chemistry Physical chemistry is the area that deals with the mechanism, rate, and energy transfer that occurs when matter undergoes a change.

Introduction to Chemistry Chemistry has 5 areas of study Analytical chemistry The area of study that focuses on the composition of matter is analytical chemistry. Physical chemistry Physical chemistry is the area that deals with the mechanism, rate, and energy transfer that occurs when matter undergoes a change.

Introduction to Chemistry The boundaries between the five areas are not firm. For example, an organic chemist uses analytical chemistry to determine the composition of an organic chemical.

Introduction to Chemistry Which area of study would you use to determine the components of an unknown liquid? physical chemistry biochemistry analytical chemistry organic chemistry

Introduction to Chemistry Pure chemistry is the pursuit of chemical knowledge for its own sake. The chemist doesn’t expect that there will be any immediate practical use for the knowledge. Applied chemistry is research that is directed toward a practical goal or application. Technological development is taking an existing material and finding a use for it.

Introduction to Chemistry Technology is the means by which a society provides its members with those things needed and desired.

Introduction to Chemistry Some of the reasons chemistry can be useful are: in explaining the natural world preparing people for career opportunities producing informed citizens

Introduction to Chemistry The word chemistry comes from the word alchemy. Alchemists were concerned with searching for a way to change other metals, such as lead, into gold. Alchemists developed processes for separating mixtures and purifying chemicals.

Introduction to Chemistry In France, Antoine-Laurent Lavoisier did work in the late 1700s that would revolutionize the science of chemistry. He helped to transform chemistry from a science of observation to the science of measurement that it is today.

Introduction to Chemistry Problem solving is a skill you use all the time. For example, a shopper must make many decisions. Some of those are based on data, like the information on a food label. The skills you use to solve a word problem in chemistry are not that different from those you use while shopping.

Introduction to Chemistry The scientific method is a logical, systematic approach to the solution of a scientific problem. The scientific method is used by everybody Some steps may include making observations, proposing and testing hypotheses, and developing theories.

Introduction to Chemistry When you use your senses to obtain information, you make an observation. Observation is an essential step in the scientific method.

Introduction to Chemistry After you make an observation, you may form a hypothesis A hypothesis is a testable explanation for an observation.

Introduction to Chemistry The procedure that is used to test a hypothesis is an experiment The variable that you change during an experiment is the independent variable. The variable that is observed during the experiment is the dependent variable. Every experiment has a control, it is what remains the same.

Introduction to Chemistry During an experiment, observable information that is collected is called data. Two types of data are quantitative and qualitative. Quantitative data uses numbers. Qualitative data uses words.

Introduction to Chemistry For the results of an experiment to be accepted, the experiment must produce the same result no matter how many times it is repeated, or by whom. This is why scientists are expected to publish a description of their procedures along with their results.

Introduction to Chemistry Once a hypothesis meets the test of repeated experimentation, it may be raised to a higher level of ideas. It may become a theory. A theory is a well-tested explanation for a broad set of observations.

Introduction to Chemistry Theories are only explanations for why something occurs A theory can never be proved However that does not mean that a theory is unreliable. Sometimes new information may cause the theory to be modified or discarded.

Introduction to Chemistry A scientific law is a concise statement that summarizes the results of many observations and experiments. A law doesn’t try to explain the relationship it describes. That explanation requires a theory.

Introduction to Chemistry The figure below shows how scientific experiments can lead to laws as well as theories. Experiments An experiment can lead to observations that support or disprove a hypothesis. Theory A theory is tested by more experiments and modified if necessary. Hypothesis A hypothesis may be revised based on experimental data. Observations Scientific Law A scientific law summarizes the results of many observations and experiments.