F6 - Chemistry and Chemical Safety

the daily functioning of our bodies is based on:

chemical reactions

chemistry

the science that deals with the composition, structures, and properties of matter and how matter changes under different conditions

matter

any substance that occupies space and has mass

matter exists in the form of:

solid, liquid, or gas

element

the simples form of chemical mater, contains only one type of atom. It cannot be broken down into a sumpler substance without a loss of identity

matter has physical properties that we can:

touch, taste, smell, or see

how many elements are known in science today?

118

how many elements occur naturally on Earth

98

synthetic elements

elements producted artificially or through synthesis

how many synthetic elements are there?

20

what is each element identified by?

a letter symbol

true or false? water, air, and your body are completely composed of chemicals

true

organic

a substance that contains the element carbon

atoms

the basic unit of matter, with a nucleus at the center surrounded by negatively charged electrons that move around the nucleus in orbits

electrons

subatomic particles with a negative charge

protons

subatomic particles with a positive charge

neutrons

subatomic particles with no charge

what does the nucleus consist of?

protons and neutrons

what determines the element?

number of protons

molecule

a chemical combination of two or more atoms in definite (fixed) proportions

what atoms is water made from

hydrogen and oxygen atoms

elemental molecule

a molecule containing two or more atoms of the same element in definite (fixed) proportions

compound molecules

also known as compounds, chemical combinations of two or more atoms in different elements in definite (fixed) proportions

physical change

a change in the form or physical properties of a substance without a chemical reaction or the creation of a new substance

chemical change

a change in the chemical composition or makeup of a substance, create new chemical substances

physical properties

characteristics that can be determined without a chemical reaction and do not involve a chemical change in the substance

examples of physical properties

color, soluility, odor, density, melting point, boiling point, hardness, and glossiness

chemical properties

characteristics that can be determined only by a chemical reaction and involve a chemical change in the substance

examples of chemical properties

ability of iron to rust, wood to burn, or hair to change color with haircolor and hydrogen peroxide

pure substance

a chemical combination of matter in definite (fixed) proportions

compounds and elements

physical mixture

a physical combination of matter in any proportion

what are examples of uniform physical mixtures?

air, salt water, hydrogen peroxide

what are the types of mixtures?

uniform and nonuniform (most beauty products)

solutions, suspensions, and emulsions are all:

physical mixtures

solution

a stable, uniform mixture of two or more substances

solute

the substance that is dissolved in a solution

solvent

the substance that dissolves the solute and makes the solution

solubility

ability to blend

why is water known as the universal solvent?

it has the ability to dissolve more substances than any other solvent

miscible

liquids that are mutually soluble, meaning that they can be mixed together to form solutions; will stay mixed and will not separate when left still

characteristics of solutions

miscible, no surfactant, small particles, stable mixture, usually clear

examples of miscible liquids

water, alcohol

immiscible

liquids that are not capable of being mixed together to form stable solutions

separate when left sitting still

form suspensions

what is an example of immiscible liquids?

water and oil

suspension

unstable physical mixture of undissolved particles in a liquid; separates over time

characteristics of suspensions

slightly miscible; no surfactant; larger particles; unstable, temporary mixture; usually cloudy; must shake before use

emulsion

an unstable physical mixture of two or more immiscible substances plus an emulsifier which binds the materials together; can separate slowly over time

emulsifier

an ingredient that brings two normally incompatible materials together and binds them into a uniform and fairly stable mixture

a properly formulated emulsion, stored under ideal conditions, can be stable for up to ___

3 years

characteristics of emulsions

immiscible, surfactant, largest particles, limited stability through an emulsifier, usually a solid color

examples of solutions

witch hazel, decongestant cleanser, equalizer

examples of suspensions

nail polish, glitter in nail polish

examples of emulsions

shampoos, conditioners, hand lotions

surfactants

substances that allow oil and water to mix, or emulsify; a type of emulsifier

parts of a surfactant

hydrophilic head, lipophilic tail

hydrophilic

capable of combining with or attracting water

lipophilic

having an affinity for or an attraction to fat and oils

oil-in-water (O/W) emulsions

oil droplets are emulsified in water

surfactant molecules have lipophilic tails pointing in and hydrophilic heads pointing out

do not feel greasy because the oil is hidden and water forms the external portion of the emulsion

which emulsion do salons, spas, and barbershops typically use?

O/W emulsions

water-in-oil (W/O) emulsions

water droplets are emulsified in oil

hydrophilic heads point in, lipophilic tails point out

feel greasier because the water is hidden and oil forms the external portion of the emulsion

powders

physical mixture of one or more types of solids

volatile alcohols

alcohols such as isopropyl alcohol and ethly alcohol that evaporate easily

fatty alcohols, such as cetyl alcohol and cetearyl alcohol

nonvolatile alcohol waxes that are used as skin conditioners

alkanolamines

alkaline substances used to neutralize acids or raise the pH of many hair products

ammonia

a colorless gas composed of hydrogen and nitrogen that has a pungent odor

glycerin

a sweet, colorless, oily substance that is used as a solvent and as a moisturizer in skin and body creams

silicones

made of silicon and other elements

a special type of oil used in hair conditioners, water-resistant lubricants for the skin, and nail polish dryers

less greasy and form a breathable film that doesn’t cause comedones; gives a silky, smooth feeling to the skin

volatile organic compounds (VOCs)

contain carbon (organic) and evaporate very easily (volatile)

overexposure

prolonged, repeated, or long-term exposure to certain product ingredients can cause sensitivity in some people

overexposure principle

describes how overexposure determines toxicity

the dose of a substance determines whether it will have a negative, poisonous effect on the body

pH

potential hydrogen

represents the quantity of hydrogen ions

ion

an atom or molecule that carries an electrical charge

ionization

the separation of an atom or molecule into positive and negative ions

anion

an atom with a negative electrical charge

cation

an ion with a positive electrical charge

H+

hydrogen ion, acidic

the more hydrogen ions in a substance, the more acidic it will be

OH-

hydroxide ion, alkaline

the more hydroxide ions in a substance, the more alkaline it will be

why is pH possible?

the ionization of water

what do products need to have a pH

must contain water

pH of pure (distilled) water

neutral pH

equal balance of 50% acidic and 50% alkaline

what does pH balance?

acidity and alkalinity; as acidity increases, alkalinity decreases

pH scale

used to measure the acidity and alkalinity of substances

range of 0 to 14, pH 7 is neutral

acidic solution

pH below 7

alkaline solution

pH above 7

what kind of scale does pH use?

logarithmic scale, a change of one whole number represents a tenfold change in pH

what happens if you give a client with dry, dehydrated skin a product that is too acidic?

could further dry and irritate their skin

what happens if you give a client with oily skin a product that is slightly alkaline?

may contribute to oil and sebum buildup and possibly create acne, may need a product with a more acidic pH

alpha hydroxy acids (AHAs)

derived mostly from milk or fruit sugars, examples of acids often used to exfoliate the skin and to help adjust the pH of a lotion, conditioner, or cream

glycolic acid

an alpha hydroxy acid used in exfoliation and to lower the pH of products

alkalis

bases, compounds that react with acids to form salts, have a pH above 7

sodium hydroxide

lye, a very strong alkali used in chemical hair relaxers, callous softeners, and drain cleaners

acid-alkali neutralization reactions

occur when an acid is mixed with an alkali in equal proportions, balancing the total pH and forming water and salt

oxidation-reduction

redox

a chemical reaction in which oxidation and reduction take place at the same time

oxidizing agent

a substance that releases oxygen

what is an example of an oxidizing agent

hydrogen peroxide

reducing agent

a substance that adds hydrogen to a chemical compound or subtracts oxygen from the compound

exothermic reaction

when a reactions releases energy in the form of heat

combustion

the rapid oxidation of a substance accompanied by the production of heat and light

endothermic reaction

a chemical reaction that requires the absorption of energy or heat from an external source for the reaction to actually occur

eg. melting ice

incompatible products

products that should not be mixed or stored near each other