eleventh paper Flashcards
(32 cards)
since elements always combine in fixed rations, this lends support to the idea of elements being made of _____ ______
discrete particles
what was JJ Thompsons experiment
he placed a positively charged plate on one side of a tube and a negatively charged plate on the other side. The beam was deflected away from the neg. plate towards the pos. plate.
What did thompson realize from his experiment?
the particles that made up the bean must be negatively charged, since like charged repel and opposites attract
what were the particles Thompson discovered later called?
electrons
was the beam that thompson experimented with light?
no, could’nt be because of its different properties
the nucleus contains the most of the atoms ____
mass
the most of atoms volume is ____ ____
empty space
in 1900 max plank introduced the idea that matter ___ and ____ energy in discrete units called _____
emits
absorbs
quanta
in 1905 albery Einstein extended the quantum concept to include ____ and that ___ consists of discrete units called _____
light
light
photons
the energy of a photon is directly proportional to the ….
frequency of vibrations
define the continuous spectrum
when light shines through a prism the light is seperated into a continuous band of colours.
light from what 3 things produce a continuous spectrum?
1) incandescent solids
2) liquids
3) dense gases
what does light from an incandescent gas produce?
a line spectrum
what does light from a cold gas interacting with white light produce?
dark line spectrum
two examples of emission spectra
aurora borealis
neon sign
what does atomic hydrogen produce?
a series of characteristic line spectra in the ultraviolet, visible, and infrared parts of the total spectrum.
what 4 things does the visible light spectra always consist of?
2 violet lines
a blue green line
bright red line
bohrs theory suggested what 2 things?
allowed orbitals and radiationless orbits
define allowed orbitals
an electron can only orbit around an atom in a specific orbit
define radiationless orbits
an electron in an allowed orbit does not emit radiant energy as long as it remains in the orbit
define quantum leaps
an electron gains or loses energy only by moving from one allowed orbit to another
the lowest energy states are called …
ground states
the highest energy states are called…
excited states
what happens each time an electron makes a quantum leap moving from a higher energy orbit to a lower energy orbit?
it emits a photon of a specific frequency and energy value
