Lab Write-Up Each student (not one per group) should write down your lab write-up as follows:  Name, Name of members in group  Date, Period  Objective: Determine what will happen when a nail is placed in soda for a few days.  Hypothesis/Prediction  Procedure that you followed (What did you do?)  In paragraph form, answer these questions: What was your independent variable? What was your dependent variable? What was the control group? What were your results? Be specific. How would you improve this experiment?

Science Is a Process – Scientific Method Science is a method for learning about nature. The scientific method works like this:  Idea  Hypothesis  Prediction  Test

Introductory Science Math Scientific Notation Metric system, metric conversions Significant Figures

Atomic Structure Three primary subatomic particles.  Proton  Neutron  Electron

Historical Models Dalton's Model Thomson's Model Rutherford's Model Bohr's Model Electron Cloud Model

Inside the Nucleus Nucleons  Protons  Neutrons Protons  Positive charge  Mass = 1 amu  Determine the element Neutrons  Neutral charge  Mass = 1 amu  Determines the isotope

Electrons Outside the nucleus In a surrounding cloud Mass = 1/1836 amu Heisenburg Uncertainty Principle  Can never know exactly where they are AND how fast they are going  Only know a probable location  Electron shells, subshells, spin

Table for Subatomic Particles

Notation Chemical symbol – found on Periodic Table Atomic Number – number of protons Atomic mass – number of protons + number of neutrons Charge – shows charge on atom

Vocabulary Substance – matter with a uniform and unchanging composition; pure substance Element – a pure substance that cannot be be broken down into simpler substances by physical or chemical means (e.g. hydrogen, oxygen) Compound – a chemical combination of two or more different elements; can be broken down into simpler substances by chemical means and has properties different from those of its component elements (e.g. water)

Hydrogen/Oxygen/Water Would you put oxygen or hydrogen on a fire to put it out? Can you breathe in water?

Hydrogen/Oxygen/Water At room temperature, hydrogen and oxygen are a gas. At room temperature, water is a liquid. Four states of matter: Solid, Liquid, Gas, Plasma. Each element and compound has a different temperature that causes them to change phase.

Vocabulary Mixtures – a physical blend of two or more pure substances in any proportion in which each substance retains its individual properties; can be separated by physical means  These physical means include: filtration, distillation, crystallization, sublimation, and chromatography  This includes heterogeneous and homogeneous mixtures.

Vocabulary Filtration – uses a porous barrier to separate solids from liquids (e.g. water filters) Distillation – heats substance until one boils into a vapor, leaving the other substance (e.g. boiling salt water to separate water and salt) Crystallization – Forms pure solid particles of a substance from a solution containing the dissolved substance (e.g. sugar water to rock candy)

Vocabulary Sublimation – when solids turn to vapor, not melting. It skips the liquid phase. Chromatography – separates components of a mixture based on the ability of each component to travel or be drawn across the surface of another material (demo)

Elements and Compounds Elements are found on the period table. Compounds are combinations of elements with a given proportion. How do you separate a mixture? Physical Change – essentially a change that occurs which can be reversed (e.g. changing phase of matter, cutting a piece of paper) How do you separate a compound? Chemical Change – essentially a change that occurs that cannot be reversed (e.g. rust, rotting food)

Physical/Chemical Changes Physical changes can typically be reversed. Chemical changes cannot be reversed. Evidence for chemical changes: Change in color A gas is produced A precipitate is produced Chemical properties: Flammability – a material’s ability to burn in the presence of oxygen Reactivity – how readily a substance combines chemically with other substances

Characteristics of Matter MATTER MixturesSubstances HeterogeneousHomogeneousElementsCompounds MixturesMixtures Chemical Changes

Proportions Law of Definite Proportions – a compound is always composed of the same elements in the same proportions by mass, no matter how large or small the sample. H 2 O will always have two parts hydrogen, one part oxygen. Percent by mass – the ratio of the mass of each element to the total mass of the compound Percent by mass (%) = mass of element x 100 mass of compound

Proportions Law of Multiple Proportions – when different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other elements in a ratio of small whole numbers e.g. Water (H 2 O) and hydrogen peroxide (H 2 O 2 ) – the same elements can form different compounds based on proportionality

Water and Hydrogen Peroxide have very different properties.

Orbitals

Periodic Table for Electron Configuration