Chem Review

What is this symbol?

Flame

• May easily catch on fire and burn rapidly. Fire requires a fuel source, O2, and heat in order to burn. Keep these elements away from each other to reduce risk of fire.

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Flame over circle (Oxidizing)

• Contains O2 which creates more intense flames. Use in well ventilated areas, and keep away from any open flames.

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Skull and Crossbones

• Can be toxic, harmful, or fatal if contact with the human body is made.

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Exclamation Mark

• Causes less severe health hazards, and effects are reversible.

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Biohazardous

• Contains organisms that can cause disease in either animals or humans.

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Environment

• Can have a negative impact on the environment.

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Exploding Bomb

• May become explosive if not handled in proper conditions (such as temperature or light). Be aware of the proper workspace to use these products.

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Corrosive

• Can chemically damage or destroy metal and skin. Damage is irreversible.

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Health Hazard

• Causes chronic health effects after long-term exposure. Use proper PPE when handling this product.

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Gas Cylinder

• contains gasses stored under pressure. Keep away from any flammable materials and use only what’s necessary.

MSDS

Material Safety Data Sheet. Contains specific information about the material.

Malleability

ability to be beaten or rolled into sheets without crumbling

Ductility

ability to be stretched without breaking

solubility

able to dissolve

magnetism

magnetic attraction between objects

Chemical Properties

describes the reactivity of a substance

behaviour in air

tendency to degrade, react or tarnish

Reaction with water

tendency to corrode or dissolve

reaction with acid

corrosion, sometimes bubble formation

Pure substance

all particles that make up the substance are identical. may be compound of element.

Heating

Temporary sterilization. kills micro-organisms. ex. canning

Freezing

Preserves indefinitely and prevents growth of micro-organisms

Salting

Way to preserve meat and fish. Draws out water from meat//bacteria and dries it.

Fermentation

Biochemical preservation technique. Bacteria converts the starches and sugars into alcohol and CO2.

Aristotle beliefs

all matter was compound of combinations of fire, water, and air.

Democritus beliefs

matter was made up of tiny particles that could not be divided into smaller pieces

Robert Boyle

all gases are made up of tiny particles that group together to make a different substance

Antoine Lavoisier

discovered mass to neither produced nor lost during the chemical reaction, called it Law of Conservation.

John dalton

thought all atoms were small spheres that had different properties. They varied in size, mass, and color.

J.J Thomson/Thompson

discovered electron. Suggested that atoms are spheres of positive charge in which negative charges were imbedded. The negative particles are electrons. (Plum Pudding Model)

Ernest Rutherford

Suggest that atoms are mainly empty space which positive charges passed. Said each atom had a tiny positively charged core which he named Nucleus.

Neil Bohr

proposed that electrons surrounded the nucleus in specific energy levels. shows that electrons at different energy levels.

Quantum Mechcanical Model of the atom

Uses mathematical probability. electrons “occupy the whole space all at once”. Electron clouds surrounds nucleus.

element

a pure substance that cannot be broken down into other substances

compound

a chemical combination of 2 or more elements in a specific ratio

Mixture

a combination of pure substances

mechanical mixture

diff substances are visible

suspension

mixture with components of diff states

Colloid

similar to suspension but suspended substance cannot be easily separated from the other substance

Solutions

all look the same. 1 substance is dissolved into another

Chemical reaction

a process that occurs when a substance(s) react to a diff substance. always results in new substances with new properties. energy is always absorbed or released during a chem reaction.

water

H2O

hydrogen peroxide

H2O2

Ammonia

NH3

Sucrose

C12H22O11

Methane

CH4

Propane

C3H8

Methanol

CH3OH

Ethanol

C2H5OH

Metals (4)

most elements

silver/gray & shiny

conductors of heat& electricity

Most solid at room temp

Non metals

17 elementa

grouped based on their differences from metals.

Invert = noble gases

Metalloids

remaining metals

staircase

Group 1

Akali metals

Soft, shiny, very reactive with water

compounds white and soluble in water

Group 2

Akaline Earth Metals

Shiny silver

White compounds but not as soluble

Group 3-12

Transition metals

Vary in everything

Group 16

Chalcogens (oxygen group) Non-metals are smaller, the metals are larger. reactive

Group 17

Halogens

non-metals

very reactive

react with alkali metals to make salts

Group 18

Noble gases

non metals

very unreactive (inert)

Periods

horizontal row of elements. atomic size decreases from left to right and atomic mass increases left to right

To find Neutrons

number of neutrons = mass number - atomic number

atomic mass

avg mass of all atoms in a element

atomic number

number of protons

mass number

sum protons and neutrons in an element

Isotope

atoms of the same elemt with different number of neutrons

Energy levels

a region of space around the nucleus that is available for electrons. Increase energy when they get further from the nucleus.

Ionization

the gaining or losing of electrons process. results in positively charged ions or negatively charged ions.

Cation

positive ion. usually metal. ion loses electrons thus having more protons.

Anion

negative ion. usually non metal. gains electrons thus having more electrons.

Covalent bonds

atoms share electrons so no transfer. how molecular compounds bond.

Diagnostic tests

proving a specific reaction has occured by observing the changes in properties of the substances involved in reaction

Common diagnostic tests

change in appearance, odour, state, pH, energy, mass, and bubbles formed.

Properties of ionic compounds

high melting point, crystalline, conductive, and soluble in water

Properties of molecular compounds

waxy, soft, not conductive, lower melting point, insoluble

Aqueous (aq)

when something is really soluble

Solid

when something is slightly soluble/ doesnt dissolve

Properties of water

polar. unequal sharing of electrons, water molecules are attracted to one another , high boil temp, bodies of water regulate temp (absorb heat + release water)

Conductivity in acids and bases

both have conductivity so they are called electrolytes.

Acid formula

H has to be on the left side of the formula or COOH on right side. state is aq.

Base

any compound with high solubility and an OH on right side

Neutralization

reaction between an acid and base which produces water and salt

energy changes

exothermic = release of energy (exit) hot

Absorption of energy (enter) cold

Formation

A+B= AB also called synthesis reaction. can also be compound + compound → compound

Decomposition

AB = A+B

Combustion

Burning in the presence of oxygen. exothermic.

Hydrocarbon combustion

CxHx + O2 = CO2 + H2O

Single replacement

A+BC = B+ AC

Double replacement

AB+CD = AD+CB

Avogadro”s number

Number of particles/mole.

Endothermic

Absorb energy. ex. ice packs

Exothermic

Release energy. ex. heat, flame, lights