Atomic Theory Flashcards
proton
-in the nucleus
-positively charged subatomic particle
nucleus
-made up of protons and neutrons
-surrounded by the electrons
neutron
-in the nucleus
-neutrally charged subatomic particle
electron
-in orbit around the nucleus
-negatively charged subatomic particle
orbit
-the path that electrons follow
protons and neutrons
-both in nucleus
-proton is positive and neutron is negative
protons and electrons
-protons in nucleus and electrons in orbits around nucleus
-protons positive and electrons negative
neutrons and electrons
-neutrons in nucleus and electrons in orbits around nucleus
-neutrons neutral charge and electrons negative
atomic number
-found above an element on the periodic table
-the number of protons in an element
mass number
-sum of neutrons and protons
-found below the elements symbol
isotope
-an atom with more or less neutrons than found on the periodic table
how is the Periodic Table organized?
-by increasing atomic number
-periods are the rows
-groups/families are columns
Alkali Metals
-Lithium to Francium
-most reactive
-only found in compounds
-soft enough to cut with a plastic knife
Alkaline Earth Metals
-Beryllium to Radium
-harder and denser
-found only in compounds
-very reactive
Transition Metals
-Groups 3-12
-Hard and shiny
-good conductors
Lanthanides
-start at Lanthanum and end at Lutetium
-found in nature
-called the “rare earth metals”
Actinides
-start at Actinium and end at Lawrencium
-Uranium and Thorium found most commonly in nature
-most are made artificially
-all radioactive
Boron family
-Group 13
Carbon family
-Group 14
Nitrogen family
-Group 15
Oxygen family
-Group 16
Halogens
-Group 17
-means “salt-forming”
-combine with many different elements
-very reactive
-like to bond ith Alkali Metals
Noble Gases
-Group 18
-Inert Gases
-rarely form compounds
-do not react with other elements
metals are found…
-on the left of the “staircase”
metalloids are found…
-touching the “staircase”
nonmetals are found…
-on the left of the “staircase”
valence electrons
-number of electrons in the outermost orbit of an atom
-found by looking at the group number (except for transition metals)
Physical Properties of Metals
-Malleable (can be hammered or rolled into a flat sheet)
-Ductile (can be pulled out into a long wire)
-Thermal Conductivity (ability to transfer heat)
-Electrical Conductivity (ability to carry an electrical current)
-luster (shiny and reflective)
-high density
-solids at room temperature (except for Mercury)
-can be magnetic
Chemical Properties of Metals
-tend to lose valence electrons, making them highy reactive
-react with nonmetals, not other metals
Physical Properties of Metalloids
-Solids at room temperature
-brittle
-hard
-semiconductor (can conduct an electric current under some conditions, but not all
Chemical Properties of Metalloids
-somewhat reactive
Physcial Properties of Nonmetals
-insulators (poor heat conductor)
-poor electrical conductor
-low density
-can be solids, gases, or liquids at room temperature
-solids are dull and brittle
-some gases are poisonous and others are necessary to life
Chemical Properties of Nonmetals
-tend to gain other valence electrons in bonding
-react with both metals and nonmetals
-some are highly reacitve, others are nonreactive
ion
-an atom or group of atoms that has lost or gained a valence electron, making it positive or negative
-neutral atom loses an electron -> becomes positive
-neutral atom gains an electron -> becomes negative
