ATOMS, MOLECULES AND IONS Flashcards
Greek philosopher who had the idea that al matter consisted of minute particles
Democritus
he coined the term atomos
Democritus
The scientist who provided precise and detailed description of the building block of matter
John Dalton
John Dalton’s atomic theory:
- An element is made up of extremely small, indestructible particles called atom
- Atoms of the same element have the same chemical properties
- Compounds are made up of atoms of more than one type of element
- Atoms are rearranged to produce different substances
3 fundamental laws of matter
- law of conservation of mass
- law of constant composition or definite proportions
- law of multiple proportions
explains that elements combine in ratios of simple whole numbers to form a compound
law of constant composition or definite properties
explains that 2 or more elements react to form two or more different compounds, with one fixed or constant element
law of multiple proportions
he carefully measured both the reactants and the products of chemical reactions
Antoine-Laurent Lavoisier
states that matter is neither created nor destroyed in a chemical reaction
law of conservation of mass
this law states that in any chemical reaction, atoms are always conserved
law of conservation of mass
negatively charged subatomic particle
electron
discovered electrons
J.J. Thomson
mass of electrons
9.11 x 10^-28g
positive charged subatomic particle
Proton
he’s famous for using the Gold foil experiment
Ernest Rutherford
mass of proton
1.6726 x 10^-24g
protons is located at the center of atom
nucleus
discovered protons
Ernest Rutherford
electrically neutral subatomic particle
neutron
discovered neutrons
James Chadwick
mass of neutrons
1.6749 x 10^-24g
contains a nucleus composed of protons and neutrons and electrons moving around the nucleus
atoms
2 ways to describe an atom quantitatively based on the number of specific subatomic particles:
- atomic number
- atomic mass
equal to the number of protons in an atom
atomic number
total amount of particles
mass number
atoms with the same number of protons but different number of neutrons
isotopes
isotopes that do not undergo radioactivity and do not disintergrate
Stable isotopes
those that exhibit radioactivity
unstable isotopes
has the same number of electrons and protons
nuetral atom
neutrality is lost during chemical changes in which an atom either lose or gain an electron to give an electrically charged species called
ions
is lost during chemical changes in which an atom either lose or gain an electron to give to ions
neutrality
when an atom gains an electron, it becomes negatively charged and is then called
anion
when an atom gives off an electron its charge becomes positive and is then called
cation
a collection of 2 or more atoms held in a specific arrangement due to sharing of electrons and acts as a single unit is called
molecule
combination of molecules of the same element
diatomic molecule
aggregate of 2 or more types of atoms
diatomic
shows the type of atom and the number constituting a certain molecule
Molecular formula
shows the order in which the atoms in the molecule are bonded
structural formula
type of perspective drawing that shows the 3 dimensional orientation of molecules
Ball and Stick Model
similar to ball and stick model but the line denotes the sharing of electrons is omitted
Space-filling model
represents 3 dimensions and is used primarily to distinguish among optical isomers
Perspective formula
formula where the symbols of atoms are listed in order as they appear in the molecule’s structure
Condensed formula
uses solid or dashed wedged bonds to depict the orientation of atoms in a molecule
Natta projection
represents bonds using solid lines
Skeletal formula
called electron dot structure; dots represent bonding of electrons and unpaired electrons
Lewis structure
used to illustrate structures or linear monosaccharides
Fischer projection
chair-like conformation commonly used to view structures of sugars
Cyclohexane conformation
used to represent structures of cyclic sugars
Haworth projection
used to illustrate a single bond between 2 carbon atoms
Newman and Sawhorse projections
The ___________ of a compound denotes the exact number of atoms present in a molecule
molecular formula
does not provide the exact number of atoms composing the molecule
empirical formula
are compounds made up of cation and anion
ionic compound
formed when cation and an anion combine due to the transfer of electrons
ionic bond
formed when 2 or more nonmetals bond by sharing valence electrons
covalent compound
a class of acid composed of hydrogen and a nonmetal
binary acid
made up of hydrogen, oxygen and a nonmetal
ternary acid
ternary acid also refers to
oxoacid