Laboratory Safety Guidelines

General Safety Rules

• Exercise caution and use good judgment in the lab.
• No eating or storing food is allowed inside the laboratory.
• Playing is prohibited inside the laboratory.
• Personal Protective Equipment (PPE) must be worn when conducting experiments.
• Long hair must be tied back.
• Closed shoes are required.
• Unauthorized experiments are not allowed.

Before an Experiment

• Know what you are working with by identifying substances and planning exposure minimization measures.
• Find and evaluate hazard information by checking the Safety Data Sheet (SDS) for your substances.
• SDS access enables preparing necessary handling protocols.
• Label chemicals properly with the name, concentration, amount, date, and owner.
• Read the lab manual in advance and consult personnel/instructor if procedures are unclear.
• Take note of reactions, quantities, and characteristics needed for the experiment.

During an Experiment

• Wear PPE correctly to protect yourself during experiments; improper use defeats the purpose.
• Ensure lab coats are buttoned, mouth and nose are covered by a mask, goggles are placed correctly, and gloves are worn.
• Give undivided attention to experiments.
• Avoid multitasking or attending to external things.
• Follow the procedure properly; do not skip or add steps in the manual.
• Consult personnel/instructors for revisions before performing.
• Record data securely; gathering data is as important as following procedures
• Data should be recorded in a separate notebook for your course/experiment.

After an Experiment

• Dispose of or store excess chemicals properly, and consult lab personnel regarding storage or disposal.
• When storing chemicals, check the SDS, lab personnel, or instructor for the proper procedure.
• Dispose of chemicals and reaction solutions properly, referring to the lab manual for proper disposal.
• Pouring chemicals in the wrong waste bottle has caused serious accidents, so chemical waste management is important.
• Clean the glassware, equipment, and work stations properly with soap and water.
• Lab equipment must be cleaned after use; wipe work stations with appropriate materials.
• Do not use lab coats to wipe spills or dry your work table.

Lab Equipments

• Beakers hold solids or liquids that will not release gases when released or reacted.
• Beaker tongs are used to move beakers containing hot liquids.
• Erlenmeyer flasks accommodate solids or liquids that may release gases during reactions or splatter when stirred/heated.
• Florence flasks are rarely used in first-year chemistry and are used for mixing chemicals and have narrow necks to prevent splash exposure.
• Graduated cylinders are used to measure volumes of liquids.
• Test tubes are narrow tubes to hold liquids.
• Test tube holders are useful for holding a test tube that is too hot to handle.
• Test tube brushes are used to clean test tubes and graduated cylinders, but forcing a large brush into a small test tube can break it.
• Test tube racks hold and organize test tubes on the laboratory counter; invert washed test tubes on the wooden pegs to dry.
• Rubber stoppers are used to close containers to avoid spillage or contamination.
• Containers should never be heated when a stopper is in place.
• Spot plates are used to perform many small-scale reactions at one time.
• Glass stir rods are used to manually stir solutions and transfer single drops of solutions.
• Forceps (tweezers) are used to pick up small objects.
• Funnels aid in the transfer of liquid from one vessel to another.
• Watch glasses are used to hold small amounts of solids, such as a product of a reaction.
• Wash bottles have a spout that delivers a wash solution to a specific area.
• Distilled water is the only liquid that should be used in a wash bottle.
• Weighing boats are used to weigh solids that are to be transferred to another vessel.
• Bunsen burners are used for heating nonvolatile liquids and solids.
• Strikers are used to light Bunsen burners, but the expensive flints should not be operated repeatedly.
• Evaporating dishes are for heating stable solid compounds and elements.
• Crucibles are used for heating certain solids, particularly metals, to very high temperatures.
• Clay triangles support porcelain crucibles when heated over a Bunsen burner.
• Crucible tongs handle hot crucibles and other hot objects, but are not for picking up beakers.
• Ring stands are safe and convenient for reactions requiring heating with a Bunsen burner.
• Utility clamps secure test tubes, distillation columns, and burets to the ring stand.
• Iron rings connect to a ring stand and provide a stable, elevated platform for reactions.
• Wire gauze sits on the iron ring to provide a place to stand a beaker.
• Double buret clamps are used to burets, long graduated tubes that are used in titration
• Triangular files cut glass rods and skill will be shared by an instructor when it becomes useful.
• Red litmus paper is used to identify bases and blue litmus paper is used to identify acids.
• Gas collecting bottles are used when a large volume of gases are produced and collected by water displacement.
• Medicine droppers transfer small volumes of liquid, less than 1 mL, and have a "rubber bulb" on top.
• Mohr pipettes measure and deliver exact volumes of liquids.
• Glass plates provide a surface for semi-microscale experiments, such as drop reactions, and for testing acids and bases.
• Spatulas dispense solid chemicals from containers; chemicals should never be transferred with bare hands.

Lesson 3: Matter

• Matter is anything that occupies space and has mass.
• Atoms are Matter's building blocks.

Properties of Matter

• Physical properties are characteristics that can be observed without changing the substance's composition. Examples: color, odor, density, boiling point, melting point

Properties Definition

• Intensive Properties: Depend on the type of matter (e.g., hardness, density, melting point).
• Extensive Properties: depend on the amount of matter (e.g., mass, volume, length).
• Chemical properties are characteristics observed when a substance undergoes a chemical change.

States of Matter

• Solid has a definite shape and volume in which particles are tightly packed. Examples: Wood, Chairs, Tables
• Liquid has a definite volume but no fixed shape and takes the shape of its container. Examples: Water, Oil
• Gas has no fixed shape or volume in which particles are far apart and highly compressible. Examples: Air, Carbon Dioxide, Nitrogen

Changes of State

• Melting: solid changing to liquid. Example: Ice melting into water
• Freezing: liquid changing to solid. Example: Water freezing into ice
• Evaporation: liquid changing to gas. Example: Boiling water
• Condensation: gas changing to liquid. Example: Rain formation
• Sublimation: solid changing directly to gas. Example: Dry ice
• Deposition: gas changing directly to solid.

Changes In Matter

• Physical change alters the physical state but not the composition. Examples: Cutting wood, Melting ice
• Chemical change alters the composition and forms a new substance. Examples: Rusting iron, Spoil food
• Reactants: Starting Substances
• Products: New substances formed

Classification of Matter

• Pure Substances: substances that have a fixed composition throughout.
• Elements are substances that cannot be broken down further. Examples: Oxygen, Gold
• Metals are good conductors and shiny. Examples: Iron, Sodium
• Non-metals are poor conductors and brittle. Examples: Hydrogen, Nitrogen
• Metalloids have both metallic and non-metallic properties.

Atomic Models

• Compounds are formed when two or more elements chemically combine. Example: Water (H2O)
• Acids taste sour and turn blue litmus paper red.
• Bases taste bitter and turn red litmus paper to blue.
• Salts are formed when an acid reacts with a base
• Mixtures are combinations of substances that can be separated by physical methods.
• Homogeneous mixtures are uniform throughout. Examples: Air, Seawater
• Solutions are homogenous mixtures of a solute dissolved in a solvent.
• Heterogeneous mixtures have non-uniform composition. Examples: Salad, Halo-Halo
• Suspensions are non-uniform mixtures whose particles settle over time. Example: Antibiotic suspension
• Colloids are mixtures whose particles do not settle but remain dispersed. Examples: Toothpaste, Whipped cream

Key Scientists and Their Models

• Democritus: Proposed that matter is made of tiny, indivisible particles called "atomos"
• Empedocles: Proposed that all matter was earth, wind, fire and water
• John Dalton (1803): Developed the Solid Sphere Model and proposed Atomic Theory.
• Atoms are indivisible and indestructible, and atoms of the same element are identical.
• Joseph John Thomson: Discovered the electron through the cathode ray experiment.
• Thomson's Plum Pudding Model proposed electrons are negatively charged particles embedded in a sea of positive charge.
• Ernest Rutherford: Gold foil experiment which lead to the discovery of the nucleus.
• Atoms have a dense, positively charged nucleus with electrons orbiting it

Additional Models

• Niels Bohr: Planetary Model with electrons orbiting the nucleus in fixed paths (energy levels).
• Erwin Schrodinger: Electron Cloud Model with electrons in probabilistic regions (orbitals) around the nucleus rather than fixed paths.

Experiments and Their Impact

• J.J. Thomson: Used a cathode ray tube to discover electrons
• Ernest Rutherford: Gold foil experiment to show a dense nucleus and atoms mostly empty space

Periodic Table Basics

• Elements: 90 occur naturally and 28 are synthetic. Symbols: Unique single capital letter or one capital followed by one or two lowercase letters.
• Atomic Number: The number of protons which is unique for each element
• Atomic Mass: The sum of protons and neutrons
• Valence Electrons: Electrons in the outermost energy level that are crucial for bonding.
• Isotopes: Atoms of the same element but different amount of neutrons.
• Groups/Families (Columns): Elements with similar properties and the same number of valence electrons.
• Periods (Rows): Properties change significantly across

Elements

• Metals are good conductors, shiny, ductile, malleable, and react with water.
• Non-Metals are poor conductors, brittle, dull, and often gases.
• Metalloids have properties of both metals and non-metals and are semi-conductive.

Important Chemical Families

• Hydrogen is a unique elements that needs 2 electrons for a full shell.
• Alkali Metals (Group 1): Have 1 valence electron, are very reactive, and are soft.
• Alkaline Earth Metals (Group 2): Have 2 valence electrons and are reactive.
• Transition Metals are familiar metals like copper and iron, and are good conductors with colorful compounds.
• Boron Family: 3 valence electrons and includes aluminum.
• Carbon Family: 4 valence electrons and includes carbon, the basis of life.
• Nitrogen Family: 5 valence electrons and mostly makes up most of our atmosphere.
• Oxygen Family: 6 valence electrons and includes oxygen, abundant and reactive.
• Halogens (Group 17): 7 valence electrons, are very reactive, and form salts.
• Noble Gases (Group 18): Have full outer shells and are inert.

Periodic Trends

• Atomic Size: Increases down groups and decreases across periods.
• Ionization Energy (IE): Decreases down groups and increases across periods.
• Electron Affinity (EA): Decreases down groups and increases across periods.
• Electronegativity (EN): Decreases down groups and increases across periods.
• Metallic Property: Increases down groups and decreases across periods.

This lesson covers the essential safety rules and procedures for working in a laboratory. It includes guidelines for general safety, preparation before experiments, and safe practices during experiments. Emphasis is placed on PPE, chemical handling, and emergency procedures.