modern atomic theory 4.3
valence electron
an electron that is in the out-most energy level
excited state
an unstable, higher energy state of an atom
dalton
atoms combine in whole number ratios 1803
Niels Bohr (1913)
believed electrons moved around the nucleus in fixed orbits at constant speed
Erwin Schrodinger (1926)
believed electrons were free to move within less restricted orbital regions
how are bohr's atomic model & rutherford's atomic model similar?
both include a nucleus at center
according to schrödinger, the area where an electron is most likely to be found is called the electron ________
cloud
thomson
electron 1897
what did erwin believe?
electron clouds
schrödinger
electron clouds 1926
in the bohr model of the atom, ________ move in fixed orbits around the nucleus
electrons
when an atom gains or loss energy, some of its ___________ may move between energy levels
electrons
niels bohr was most interested in studying __________
electrons & their behavior
what did neil's bohr discover
energy levels
bohr
energy levels 1913
an atom where the electrons have moved to a higher energy level is described to be in a(n) _________ state
excited
boron has 5 electrons. in its ground state it has 3 electrons in its lowest energy level and 2 in the next energy level
false
each orbital can hold unlimited amount of electrons
false
electrons closest to the nucleus have the most energy
false
electrons have the same amount of energy no matter what energy level they occupy
false
electrons in the furthest orbital from the nucleus have the least energy
false
certain chemical compounds will emit colored light when placed in a flame because their electrons ....
give off light when they move to their lower energy level
when all of the electrons are in their lowest possible orbital the atom is in its _______ state
ground
what is the difference between an atom in the ground state & an atom in an excited state?
ground state has less energy & is more stable
what can you assume has happened if an electron moves to a higher energy level?
it gains energy
in neils bohr's model of the atom, electrons move ______________
like planets orbit orbiting the sun
neils bohr's model of the atom can be thought of as _____________
marble inside tennis ball inside a basketball
chadwick
neutrons 1932
rutherford
nucleus & protons 1911
how does the excited state of an atom work?
one or more of the electrons may jump to high energy levels
electron cloud
orbital regions of an electron
ground state
the most stable, lowest energy state of a particle
heating an atom will cause the electrons to move from the ground state to an excited state
true
some compounds will give off color when heated because the electrons move to a higher orbital and then release colored light when they go back to a lower orbital
true
valence electrons are the furthest from the nucleus and have the highest energy
true
