1. Chapter 1 Chemistry is a Physical Science

2. Objectives Define chemistry List the branches of chemistry Compare and contrast basic research, applied research, and technology Distinguish between chemical and physical properties of matter Distinguish between a pure substance and a mixture

3. Chemistry Study of the composition, structure and properties of matter –Atoms and their composition, structure and properties Study of the changes matter undergoes –Changes in bonding, charge of atoms and groups of atoms Chemistry is a science: –A systematic study of part of the universe.

4. What’s the difference? Science: Study of the universe to answer questions and understand how it works. –Basic science: carried out for the sake of increasing knowledge –Applied science: carried out to solve a particular problem Technology: Use science to make life easier or better.

5. Branches of Chemistry Organic—carbon containing compounds ( more specifically C and H containing) Inorganic—not organic Physical—relationships between energy and matter Analytical—identification of composition Biochemistry—substances and processes occurring in living things Theoretical—design and predict properties of new compounds

6. What is a chemical? A chemical is any substance with a definite (unchanging) composition May also be called a pure substance Includes elements and compounds, but not mixtures Compounds are chemical combinations of two or more elements –different characteristics than elements that make it Mixtures are blends of two or more kinds of matter –but each kind retains its unique identity and properties

7. More about mixtures Mixtures are classified as being: –Homogeneous: uniform in composition –Heterogeneous: dissimilar in composition Examples:

8. What’s the matter? Matter is anything with volume and mass. –Volume: –Mass: The basic building blocks of matter are atoms. Atoms are the smallest parts of an element that have the properties of that element. An element is a pure substance made of only one kind of atom – (more specifically with one number of protons in the nucleus)

9. Compounds Compound is a pure substance made from the atoms of two or more elements that are chemically bonded.

10. Compounds How do things go from being atoms to compounds? Chemical change occurs –A chemical change is one in which new pure substances are formed –A chemical change is caused by a chemical reaction –Example: Burning match

11. Chemical reaction Reactant + Reactant  Product + Product Reactants are the substances that exist before the reaction Products are the substances that exist after the reaction During a chemical reaction, the physical properties of the reactants may change as well as the chemical properties.

12. Chemical Properties Measurable characteristics recorded while a substance is undergoing a chemical reaction Examples: –Reactivity with oxygen –Reactivity with hydrochloric acid

13. Physical Properties Characteristics that may be observed without changing the composition of the substance. Examples are mass, boiling point, melting point, state, color, density States of matter: –Solid –Liquid –Gas –Plasma

14. Energy (E) Definition: the capacity to do work –Work is: Whenever a physical or chemical change occurs, there is an associated energy change. Think about melting ice or burning paper

15. Measurement Properties are measured using SI units SI = Systeme Internationale = metric system This is the system we will use—more detail later Length –Meter (metre) Mass –Kilogram Volume (fluid) –Liter (litre) Time –Second Quantity (number of particles) –Mole