LEC 3 Atoms Flashcards
basic particle of the chemical elements
atom
components of an atom
- protons
- neutrons
- electrons
inside the nucleus is the ____
neutrons and protons
atom means _____ in Greek
indivisible
scientist credited for proposing the atomic theory
john dalton
3 basis of dalton in his atomic theory
- law of conservation of mass
- law of definite proportions
- law of multiple proportions
the total mass present before a chemical reaction is the same as the total mass present after the chemical reaction
law of conservation of mass
in a given type of chemical substance, the elements are always combined in the same proportions by mass
law of definite proportions
if two elements form more than one compound between them, the masses of one element combined with a fixed mass of the second element form in ratios of small integers
law of multiple proportions
father of modern atomic theory
john dalton
number of protons in the nucleus of each atom of an element
atomic number (z)
total number of neutrons and protons present in the nucleus of an atom of an element
mass number (a)
atoms that have the same atomic number but different mass numbers
isotopes
positively charged particles
protons
neutral particles with a relative mass of about 1
neutrons
negative particles
electrons
the number of electrons determines its ____ and how it reacts
chemical properties
location of:
- protons
- neutrons
- electrons
- nucleus
- nucleus
- orbitals
an atom of specific isotope
nuclide
unit of atomic mass (u) essential in determining the compositions of chemical compounds
g/mole
arrangement of the electrons in an atom into orbitals
electron configuration
_____ law states that the physical and chemical properties of the elements recur in a systematic and predictable way when the elements are arranged in order of increasing atomic number
periodic law
rows in the periodic table are called
periods
columns in the periodic table are called
groups
total number of elements in the periodic table
118
period numbers correspond to the highest occupied ______
energy level
elements with ___ are organized in groups or families
similar properties
elements in A groups
representative elements
elements in B groups
transition elements
