1. CMH 101 Luca Preziati Chapter 2: Matter and Energy DEF Matter = anything that occupies space and has mass H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O < Particulate Macroscopic > < Symbolic In Chemistry, Biochemistry and Molecular Biology matter can be observed as a macroscopic or microscopic entity, imagined at the particulate level and represented using symbols Atoms are the tiny particles that make up all matter. In most substances, the atoms are joined together in units called molecules

2. Chapter 2: Matter and Energy States of Matter

3. Chapter 2: Matter and Energy < Chemical Properties are the characteristics that determine how the composition of matter changes as a result of contact with other matter or the influence of energy (chemical reaction) < Physical Properties are the characteristics of matter that can be changed without changing its composition (no chemical reaction)

4. Chapter 2: Matter and Energy Pure Substance = all samples are made of the same pieces in the same percentages – salt Mixtures = different samples may have the same pieces in different percentages. Separate into components based on physical properties – salt water Pure Substance Constant Composition Mixture Variable Composition Matter Homogeneous Heterogeneous Elements Compounds Identical atomsDifferent atomsOne phaseMultiple Phases

5. Chapter 2: Matter and Energy

6. The Electrical Character of Matter Two Kinds of Charge called + and – Opposite Charges Attract + attracted to – Like Charges Repel + repels + – repels – To be Neutral, something must have no charge or equal amounts of opposite charges

7. Chapter 2: Matter and Energy Law of Conservation of Mass Antoine Lavoisier “Matter is neither created nor destroyed in a chemical reaction” the total amount of matter present before a chemical reaction is always the same as the total amount after the total mass of all the reactants is equal to the total mass of all the products

8. Chapter 2: Matter and Energy Energy DEF Energy = anything that has the capacity to do work Law of Conservation of Energy: “Energy can neither be created nor destroyed” Kinetic Energy is energy of motion, or energy that is being transferred from one object to another Potential Energy is energy that is stored We cannot get a 100% efficient energy transformation process

9. Chapter 2: Matter and Energy The Conservation Law E = mc 2 Energy = mass x speed of light 2 Albert Einstein realized that it is also possible to transform matter in energy and vice versa. This transformation mainly happens in nuclear reactions where a tiny amount of matter in converted into an enormous amount of energy