chemistry semester 1 final

how to find the number of valence electrons

Groups on the periodic table, groups 1 and 2 have the same number as the group they are in, groups 13 and 18 are the same number as the group minus ten (helium has 2)

colombic attraction

the force of attraction between two positively charged particles

Pattern of colombic attraction on the periodic table

increases left to right

pattern of ionization energy on the periodic table

increases left to right on the period and decreases top to bottom on the group

ionization energy

the minimum amount of energy it takes to steal a loose electron from an atom

electronegativity

the ability for an atom to attract a shared pair of electrons to its nucleus

patterns of electronegativity on the periodic table

increases left to right on the period and decreases top to bottom on the group

atomic radius

the size of an electron from the center of the nucleus to the end of the electron cloud

patterns of atomic radius on the periodic table

as you move left to right on the period it decreases and as you move top to bottom on he group it increases

what color is lithiums flame

red/crimson

what color is stroniums flame

red

what color is calcium’s flame

orange

what color is sodiums flame

yellow

what color is rudibiums flame

violet/red

what color is coppers flame

green

what color is potasiums flame

lilac

what color is magnesiums flame

white

valence electron

electrons on the outermost shell of the cloud thing

the periodic table is organized by…

-increasing atomic # by period

-# of valence electrons organized by groups

-enegy levels organized by periods

periods

17 of them, correspond to the # of electron shells, atomic # increases by 1 as you move left to right .

Groups

18 of them, all have them same # of valence electrons

properties of metal

shiny

excellent conductivity

high malleability

high density

low ionization

properties of nonmetals

dull

poor conductor

no malleability

low density

high ionization

properties of metaloids

shiny or dull

semiconductor

brittle (none)

medium density (intermediate)

medium ionization (intermediate)

How to find element facts

atomic # top

symbol

name

atomic weight/mass

structure of an atom

nucleus, orbitals (electron cloud) subatomic partials (proton neutron electron)

electrical charge, mass, and location of the electron

charge- negative

mass.0005

location-orbitals (electron cloud)

electrical charge, mass, and location of the neutron

charge-neutral

mass-1

location-nucleus

electrical charge, mass, and location of the proton

charge-positive

mass-1

location-nucleus

how to calculate mass number

-protons+neutrons(Neutrons=mass#-atomic#)

-rounding atomic number

Ion

a atom with a electric charge because it gained or lost an electron

Isotope

two atoms of an element bu tone has a different number of electrons so it has a different mass number

how do isotopes change an atom

-affecting weight of nucleus

-(notation) mass number changes

how do ions change and atom

-electron cloud shrinks

-(notation)charge is added

matter

anything that has mass and takes up space/volume

properties of chemical matter

-flammability

-PH

-corrosion

-acidity

-toxicity

properties of physical matter

-color

-density

-mass

-volume

-hardness

-state of matter

evidence a chemical change occurred

-permanent color change

-heat release

-formation of precipitate

what happens at the particle level during a physical change

the formation of the particles may change but the identify stays the same

what happens at the particle level during a chemical change

the identity of the particle changes

physical property’s of solids

tightly packed particles that vibrate, takes shape of container, definite volume, low kinetic energy

physical property’s of liquids

close particles but no regular arrangement, particles can slides and flow on top of each other, takes shape of bottom of container, definite volume and medium kinetic energy.

physical property’s of gas

well separated particles and moving very fast with high kinetic energy, indefinite volume

pure substance

a constant chemical compound

mixture

a combination of two or more substances where they are combined physically but not chemically bonded

atom

the smallest unit of an element, makes up everything

element

a pure substance contain only one kind of atom

molecule

the smallest component of a chemical compound that can stand itself and contain the identity of the substance

compound

a pure substance created when two elements are chemically bonded

physical properties used to separate mixtures

-size

-buoyancy

-boiling point

-solubility

-magnetism

-state of matter

strategy used to separate mixture

-filtration

-Evaporation or Crystallization

-distillation