Unit 3 (chapter 4) Flashcards
anion
negative ions formed by gaining electrons
atom
particle that consists of a nucleus of protons and neutrons surrounded by a cloud of electrons. distinguished by protons
atomic mass
mass of the atom; weighted average of the masses of all naturally occurring isotopes of an element
atomic mass unit
a unit of mass used to express atomic and molecular weights (ex: O is 15.999)
atomic mass number
mass of protons and neutrons
cation
positive ions are formed by losing electrons
covalent bond
bond between 2 nonmetals
diatomic element
elements that when uncombined with any other element exists as a bonded pair of atoms (1+7 rule)
electron
negative charge, 0 amu, found outside nucleus
formula unit
ratios of ions held together by ionic bonds
ion
- charged particle
- ions are formed from the loss or gain of electrons
- positive ions (cations) are formed by losing electrons
- negative ions (anions) are formed by gaining electrons
ionic bond
bond between one metal and one nonmetal
ionic compound
- at least one nonmetal and one metal
- made up of formula units
isotope
atoms of the same element with different masses (because of difference in number of neutrons)
- have the same physical and chemical properties
- some are radioactive, meaning their nuclei are unstable and emit radiation
- radiation is not detectable by human sense
mass number
mass of protons and neutrons
metal
a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity
metalloid (aka semimetal)
an element whos properties are between metals and nonmetals
molecular compound
- 2 or more non-metals
- made up of molecules (neutral groups of nonmetal atoms held together by covalent bonds and connected to each other by intermolecular forces)
molecule
neutral groups of nonmetal atoms held together by covalent bonds and connected to each other by intermolecular forces
monoatomic ion
an ion consisting of exactly one atom
neuton
charge of 0, 1 amu, found inside nucleus
nonmetal
dull, found on the right of periodic table
nuclear atom
model developed by rutherford
In the nuclear atom, the protons and neutrons, which comprise nearly all of the mass of the atom, are located in the nucleus at the center of the atom. The electrons are distributed around the nucleus and occupy most of the volume of the atom
proton
positive 1 charge, 1 amu, found inside nucleus
transition metal
any of various chemical elements that have valence electrons—i.e., electrons that can participate in the formation of chemical bonds—in two shells instead of only one
atomic number
number of protons
Coulomb’s Law
describes the strength of the electrostatic force (attraction or repulsion) between two charged objects
law of conservation of matter
formulated by Lavoisier, matter cannot be created or destroyed in an isolated system
law of constant proportions
created by proust, chemical compounds are made up of elements that are present in a fixed ratio by mass
Dalton
created law of multiple proportions and Dalton’s atomic theory
law of multiple proportions
the same elements can form more than one compound in different whole number ratios
Dalton’s atomic theory
- matter is made up of atoms
- particles or atoms of an element are identical (wrong)
- atoms are indivisible (wrong)
- there are as many kinds of atoms as elements
- atoms can combine to form other elements
Michael Faraday
electricity responds to a magnet, charged. cathode has mass
Thompson
cathode ray tube, discovered electron and electron charge
Millikan
mass of electron, experimental apparatus
Thomson
Plum pudding model, atoms have a neutral charge
Rutherford
gold foil experiment, alpha particles, positively charged nucleus, discovered protons, nuclear atom model
Chadwick
discovered neutrons
