23-24 Chemistry Pre comp (copy)

In the following, please tell the type of lab equipment used

In the following, please tell the type of lab equipment used

Good luck!

Graduated cylinder

Electronic balance

Volumetric flask

Erlenmeyer Flask

Triple bean balance

Hopefully you get the point. I cant include all of them but these are the basics. Continue identifying lab equipment in your time

Biohazard

a risk to human or environmental health (e.g. virus or bacteria)

Corrosive

highly reactive substance that causes damage to living tissue or eats away a material

Flammability

ability to burn or ignite; easily set on fire

Ingestion

way that a substance can enter the body by drinking or eating it

Inhalation

way that a substance can enter the body by breathing it in

Radioactive

the giving off of rays of energy or particles after the atoms break apart

Skin Absorption

way that a substance can enter the body thru contact with skin

Toxic

poisonous

Eye wash

used to wash chemical out of the eye

Fume hood

used to ventilate hazardous or toxic fumes, vapors or dust

Gas shutoff

safety equipment used to immediately shut off gas lines in the lab

Safety Shower

used to wash away hazardous chemicals that come in contact with skin or clothing

Accuracy

an indication of how close a measruement is to its accepted value

Density

measures mass per unit volume; SI unit kg

Length

measures size; SI unit meter (m)

Mass

measures the amount of matter; SI unit kilogram (kg)

Meniscus

curve in the surface of liquids when it touches another material

Temprature

measures particle motion (average kinetic energy); SI unit Kelvin (K)

Precision

the closeness of measurements to each other

Time

measures duration of events; SI unit seconds (s)

Volume

amount of space an object takes up; SI unit m3

Weight

measure of gravitational force exerted by an object; SI unit Newtons

Beaker

A wide cylindrical container with a flat bottom used to mix and heat substances

Bunsen burner

vertical metal tube connected to gas source that produces a single flame

Electronic balance

measuring scale used to determine mass of an object or substance

Erlenmeyer flask

Conical shape container are for mixing and heating substances

Volumetric flask

Spherical shape container used to precisely make solutions

Funnel

a hallow cone used to pour substances into containers with small openings or to filter substances

Graduated cylinder

a narrow, cylindrical container marked with horizontal lines used to precisely measure the volume of liquids

Pipet

a small tube used to precisely transfer small amounts of liquid, often used to make dilutions of a substance

Test tube

a long thin cylindrical container with a U-shaped bottom used to hold or mix small amounts of material

Control Group

standard to which comparisons are made in an experiment

Experimental constant

potential variables that remain unchanged in an experiment

Independent variable

the variable that is manipulated or changed in an experiment

Dependent variable

the variable that is measured or observed in an experiment

Physical properties

are observed and measured without changing the identity of the substance.

Properties used to identify substances are color, odor, magnetism, mass, physical state

Chemical properties

can be observed or measured by changing the identity of the substance.

• Observable by breaking chemical bonds to change the substance into a new substance

Reactions with air, water, oxygen, acid or base are used to test reactivity.

Elements

Simplest type of matter

same type of atoms

Cannot be broken chemical or physical means

Compounds

2 or more elements combined chemical means

can be broken chemical not physical means

Mixture

2 or more substances not chemically combined

Can be separated by physical means

Diatomic elements

Some elements form a chemical bond between atoms of the same element

Molecul

Separation by chemical means

Heat to break chemical bonds

Electric current to break chemical bonds

Create a reaction to release elements

Separation by physical means

•Sorting or filtration

•Evaporation or distillation

•Magnetism

•Chromatography

•Crystallization

•Floatation

Homogeneous Mixture

Solutions and alloys

Same composition

Doesn’t separate on its own

Light passes thru it because particles too small

Heterogeneous Mixture

Suspensions and colloids

Different parts visible

Separates when denser particles settle to bottom

Light is blocked or scatters because particles are too large

Colloids

•Often appear homogeneous but particle size is too big

•Scatters light so classified as heterogeneous mixture or an “in-between” group

Solute

:   substance mixed into the solution

Solvent

:  substance that does the dissolving

Aqueous solutions

solutions where water is the solvent

Evaporation

A way to separate solid and liquid using heat

Decantation

Separating liquids by different densities, layer by layer

Filteration

Separates substances with particles of different sizes

Coagulation or flocculation

uses chemical properties of substances to remove dirt or unwanted material from water

Sedimentation

removal of unwanted material by letting it settle down into the water

Disinfection

add chemical like chlorine to kill remaining bacteria and viruses

Atom structure

dense positive core (middle) called the nucleus

empty space around the nucleus called electron cloud

Alkali metals

group 1, very reactive, soft, silver, shiny, low density;

Alkaline earth metals

group 2 of the periodic table which are harder and less reactive than the group 1

Anion

negatively charged ion

Atomic mass

average mass of all the forms (isotopes) of an element

Atomic #

the number of protons in an atom

Cation

positively charged ion

Charge

measure of electric charge (positive or negative) of an atom or molecule

Electron

negatively charged particle with no mass

electron cloud

area around the nucleus of the atom where electrons are most likely found

Electron shell

number of energy levels in an atom that matches the period or row of an element

Halogens

Group 7A or 17 that contains nonmetals, very reactive and poor conductors

Ion

atom or group of atoms that has a positive or negative charge

isotope

atoms of the same element that have different numbers of neutrons

Metals

malleable and ductile elements, usually solid at room temperature and good conductors

Metalloids

elements that separate metals and nonmetals on the periodic table

Noble gases

elements in Group 8A or 18 of the periodic table; least reactive elements

Nonmetal

element that are dull (not shiny) and poor conductors of heat and energy

Transitional metals

metals located in groups 3-12, moderate range of reactivity

Valence electrons

electrons in the outermost energy level of an atom