Unit 1 - Safety and Matter

SDS

SDS

Safety Data Sheet that provides printed information regarding the hazards of materials that contain chemicals

How to detect odor from chemical

waft toward nose

If a chemical spills ...

tell teacher immediately but if it gets in eyes, use the eyewash station first then tell the teacher

If a person catches on fire ...

get the emergency fire blanket

Flammable

easily set on fire, able to burn

Personal Protective Equipment (PPE)

equipment that helps protect from chemicals (goggles, apron, NOT contact lenses)

Green chemistry

the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances

Matter

anything that has mass (like kg or g) and volume (like mL or m³) (sound and light are NOT this)

International System of Units

the system of units (SI) used by scientists to measure the properties of matter

Physical properties

characteristic of a substance that can be observed or measured without changing it's composition (density, conductivity, melting point, boiling point, malleability, ductility)

Extensive physical properties

depend on the amount of matter present and include mass, length, and volume

Intensive physical properties

depend on the type of matter but not amount

Phases of matter

solid (definite shape/volume), liquid (definite volume), gas, plasma

Endothermic phase changes

melting, evaporation, sublimation

Exothermic phase changes

freezing, condensation, deposition

Chemical property

the ability of a substance to undergo a specific chemical change (burn, rot, decompose, corrode, explode, ferment)

Physical change

change in a substance that does not involve a change in the identity of the substance

Chemical change

change in matter that produces one or more new substances and energy is either given off or absorbed

4 signs of chemical change

transfer of energy (like temperature), change in color, production of gas, formation of a precipitate

Law of Conservation of Mass/Matter

matter cannot be created or destroyed ... so, chemical equations must be balanced

Pure substance

matter that has a uniform and definite composition (elements or compounds)

Element

pure substance that is the simplest form of matter that has a unique set of properties and cannot be broken down into other substances (most exist as atoms in nature expect for diatomic molecules)

Diatomic molecules

molecules made up of two atoms of the same element (H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂)

Compound

pure substance that contains two or more different elements, are represented by chemical formulas, and exits as molecules or a formula unit

Molecule

2 or more atoms bonded together

Ex: H₂, H₂O

Coefficient in chemical equations

number before the element compound which says how many molecules or atoms there are that are not all bonded together. Ex: 2H = 2 separate groups of hydrogen.

Subscript in chemical equations

amount of atoms that are bonded together and distributes if outside a parenthesis Ex: (H₂)₂ = 4 hydrogen

Mixture

combination of two or more substances that are not chemically combined (NOT pure substances)

Homogenous mixture (solution)

a mixture in which the composition is uniform throughout

Heterogenous mixture

mixture with uneven distribution of different substances

Distillation

process that separates mixtures in a solution based on their difference in boiling points Ex: salt and water

Filtration

process that separates undissolved solids from liquids based on the particle size in mixtures

Ex: sand and water

Chromatography

process that separates mixtures based on attractive forces between particle in solutions Ex: ink in a pen