Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
19 Cards in this Set
- Front
- Back
electrons do not orbit the
nucleus like planets, but can be found anywhere in the atom based on their energy level |
electron cloud theory
|
|
all eloments are composed of atoms that cannot be divided
|
Dalton
|
|
countered thomson's modle, inferred that an atoms positive charge must be clustered in a tiny region called the nucleus
|
rutherford
|
|
proposed that an atom consists of negative charges scattered throughout a ball of positive charge
|
thomson
|
|
states that electrons have only certin amounts of energy and can only move in certain orbits
|
Bohr
|
|
describes an atom as consisting of a nucleus that contains protons and neutrons surrounded by a cloud-like region of moving electrons
|
Modern atomic theory
|
|
the smallest partical of an element
|
atom
|
|
a tiny region in the center of an atom
|
nucleus
|
|
negatively charged particles in an atom
|
electron
|
|
positively charged particles in an atom
|
proton
|
|
the unique number of protons in the nucleus of an atom
|
atomic number
|
|
the sum of protons and neutrons in the nucleus of an atom
|
mass number
|
|
atoms with the same number of protons but a different number of neutrons
|
isotopes
|
|
the Average mass of an element's atom
|
Atomic mass
|
|
the elements arranged in a regular repeating pattern
|
periodic table
|
|
vertical columns of elements with similar characteristics
|
groups
|
|
horizontal rows of elements with similar characteristics
|
periods
|
|
a process in which 2 atomic nuclei combine forming a larger nucleus and releasing huge amounts of energy
|
nuclear fusion
|
|
when a large star explodes producing more heavy elements
|
supernova
|