Chem I Review 2

each element is made up of very small units of matter called "Atoms"

the basic structural unit of an element, the smalles portion of an element that retains all the properties of that element. these are the particles which actually "combine" with other particles to form a compound.

Nucleus and Orbits or Shells

a very dense, small, positively-charged center of an atom that contains most the atom in the form of protons and neutrons, a solid core

the area outside the nucleus where the elctrons are found, both of these being made up of subatomic particles

• protons
• neutrons
• electrons

(positively charged) particles found in the nucleus of an atom, always at least one, mass of 1 any (unit), charge of +1

uncharged particles found in the nucleus of an atom, mass of 1 amu, no charge (neutral)

(negatively charged) particles found in the shells or orbits surroundings the nucleus, mass of 1/1837 amu, we will consider it to be zero, has a charge of -1

the number of protons in the nucleus of an atom or the number of electrons in the shells of an uncombinded atom

• the weight given a atom
• the sum of the weights ofthe electrons, protons & neutrons

the electrons are always found arranged in a particular order around the nucleus of an atom, this order is called electronic configuration

• can only contain a certain number of electrons
• the first energy level must be completely filled before electrons may fill the second energy level and so forth

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electrons found in the outermost shell of an atom, they are also the particles that will actually be combining with like particles of anothe atom to bond the atoms together and form a compound

chemical properties as well as many of it's physical properties

the attraction between the nucleus & the valance, what holds the electrons around the nucleus (keeps from floating away)

• developed to attempt to group the elements according to similar properties and types of reactions
• the elements are arranged horizontally (in rows) in order of increasing atomic number
• they are also grouped together vertically (in columns) according to their similar chemical properties
• called groups or families

• are denoted with roman numberals, ea. member of a group is "related" to the other members because:
• 1. they have similar chemical properties
• 2. they have same number of valence electrons

the elements are arranged horizontally (in rows) in order of increasing atomic numberthey are also grouped together vertically (in columns) according to their similar chemical propertiescalled groups or families

the electrons of other atoms

lose their valance electrons

gain valance electrons

• Group I= Alkalis
• Group VII (7)= halogens (salt formers)
• Group VIII (8) or O= Inert Gases or Noble Gases (will not react)

a combination of two or more atoms , these could be of the same element or they could be atoms of different elements that form a compound.

a group of symbols that represents all the elements present in a compound or molecules.

how many atoms there are

are uncombined elements together to make up the compound of the molecule

• form molecules with themselves in order to be stable
• ex. oxygen, hydrogen, chlorine and nitrogen

anything thats compound of 2 atom

anything that contains several atoms (or anything more than two atoms)

only the noble gases can stand along on their own (means one)

a "charged" atom it has either a positive or negative charge

the breaking apart of a compound into ions when placed in solution

• 1. Cation
• 2. Anion
• 3. Polyatomic ion or Radical

an atom that has lost electrons when an atom loses electrons it becomes positvely charged

an atom that has gained electrons when an atome gains electrons it becomes negatively charged

a charged group of atoms that stay together & act as a single unit in chemical reactions

• Ammonium
• Bicarbonate
• Carbonate
• Cyanide
• Hydroxide
• Hypochlorite
• Nitrate
• Nitrite
• Sulfate
• Sulfite
• Phosphate
• Phosphite

NH4

HCO3

CO3

CN-1

OH-1

OCI-1

NO3

NO2

SO4

SO3

PO4

PO3

is when ions are formed, they take on the electronic configuration

achieve a full outermost shell so they will lose or gain electrons to do this

• the combining capacity
• the valance / the Group
• or the oxidation number

an abbreviated represenation for the structure of an atom, the symbol stands for the nucleus and all of the energy levels except for the outermost

valence electrons

• has one valence electron, in order to gain stability, it will tend to lose this electron to achieve a full outermost shell of eight electrons
• (when it loses/overbalance it is positively charged particle an ion, cation)

• has seven valence electrons in order to gain stability, it will tend to gain an electron to reach a full outermost shell of eight electrons
• (when anything is gained/overbalanced it becomes negatively charged particle and ion, a anion)

• metals
• non metals

• conduct heat & electricity
• have a luster (shine)
• some area ductile (shaped)
• some are malleable (bent)
• most are solids

is a liquid and a exception to most metal physical properties

positive electrical charge and tend to be based formers

• not good conductors
• usually brittle
• not malleable
• not ductile
• some are solids, some liquids, some gases

negative electrical and tend to be acid-formers

right side of the Periodic Table includes the groups: Halogens and the Noble or Inert Gases

substances composed of two or more elements combined chemically in definte proportions by weight, only seperated by chemically, carrying both chemical and physical properties different from the constituent elements

• NaCl-Salt
• CO2-Carbon Dioside
• H2O-water
• HCHO-formaldehyde

two or more substances put together but, not chemically combined, elements or compounds may be present in any proportion, seperated by physical means

• coffee(cmpd)
• water (cmpd)
• sugar (cmpd) all put together make a mixtures
• embalming fluid (mixture)
• blood
• milk
• air (water, oxygen, CO2, etc.)
• saltwater (salt & water)

dissolved in water and mixed with all the other constituents