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