CHAPTER 2 MATTER

What is Matter? Page 38 Chemistry The study of matter and how it changes

Vocabulary pg Elements Atom Compound Molecule Figure 2-3

What are atoms? Electron arrangement in atoms is the largest determining factor of properties Determine the properties of all matter

What’s in an Atom?Atom Page 72 Nucleus Proton Neutron Electron

Orbitals (Page 75) Four kinds - S, P, D, F Hold maximum of 2 electrons Electrons occupy lowest energy levels available Valence electrons page 76

No Overall Charge Equal number of protons and electrons Charges cancel No net charge (neutral) Page 72 figure 3-3

Counting Atoms Moles (Page 96) Avogadro’s constant x particles = 1 mole

Compounds Different from the elements it contains Elements always combine in the same proportions Every compound is also a molecule

Molecules Atoms combine and act as a unit Most made of atoms of different elements (figure 2-4) Can be made from one element (figure 2-5)

Pure Substances Page 41 Elements and Compounds are pure substances Can not be broken down by physical actions

Mixture Page 41 Grape Juice is a mixture Can be separated Liquids, solids or gases Classified by how completely the substances mix

Mixtures Heterogeneous Not uniformly mixed Homogeneous Mixed the same throughout

Liquid Mixtures Miscible Homogeneous Looks pure Immiscible Heterogeneous Can see 2 layers

Chemical Formulas Shows how many atoms of each element are in the basic unit of a substance Subscript = # atoms Figure 2-6 page 41

Section 2.1 Review Page 44 Questions 1- 8

Cookie Assumptions Molecules and atoms can move Move faster as temp rises Kinetic Theory of Matter

Page 45 3 main points Helps visualized three common states of matter Solid, Liquid, Gas

States of Matter Page 46 figure 2-10 Differ in distances and angles between molecules or atoms And in how closely particles are packed together

Gases Spread in all directions (fluid) Can exert Pressure Force exerted per unit area of a surface Figure 2-11

Solids Have a rigid structure Particles have almost no freedom to change position And are held closely together by strong attractions Still vibrate around fixed spot

Liquids Particles are close together But have more freedom of movement Spread out on its own (fluid) Viscosity (page 48)

Energy Adding or transferring causes Melting Evaporation Condensation Sublimation

Changing state does not change composition or mass

Page 51 figure 2-17 Conservation of Mass Conservation of Energy

Section 2-2 Review Page 52 Questions 1-8

Properties of Matter

Chemical Properties Page 53 Involves the reactivity of elements or compounds Page 54

Physical Properties Melting Points (page 52) Boiling Points Density Heavy or light? Float or sink?

Density Equation - D=m/V Density = mass / volume Expressed as grams/cm 3 or grams/mL Buoyancy (page 57)

Changes Chemical Change Change in composition or Separation of pure substances Law of Conservation of Mass

Changes Physical Change Energy absorbed / released No change in composition Dissolving = physical change Page 60 fig 2-23

Section 2-3 Review Page 60 Questions 1-7