Chapter 9 - Lecture Flashcards
Endothermic, These days, Helium - inert
Helium gas is inert, but Hydrogen is reactive. Electrons. Models to help us understand why helium and other noble gases are unreactive as opposed to other elements in periodic table.
Light
- Electrons and atoms- understanding- complicated subject
- travels fast ; see lightning before hear thunder- light travels faster than sound, 2.9 x 10 8- light- 340 m/s;
- convert 340 m/s 3.4 x 10^2- m/s
- Light is 6 times faster- C-
in a vacuum
2.998 x 10^8 m/s
Light
Light is a form of electromagnetic radiation-
- Electric Field
- Magnetic Field
When you combine them you get light, you get electric magnetic radiation- combination of electric fields and magnetic fields- both waves- light behaves like a wave-
wavelength- between two crests or two troughts- lambda
amplitude
relates to intensity of light; vertical peak of that crest
wavelength
gives- a lot of information about energy, color, whether we can see that light or not-
we will be paying more attention
2 waves- longer wavelength- the bottom one- shorter wavelength
frequency
how often a wave passes through a fixed point- often- high frequency- low frequency-
the longer the wavelength, less than frequency, lambda,
how many cycles of waves passing through in a second
the frequency, units, hertz- units of one / second -
lambda x v= inversely proportional -
lambda (m) = v (1/sec)
c= m/sec
Rainbow
See them after rain- rain drops or mist- sunlight- in order for a rainbow to show up- when sunlight passes through droplets of water in the air, light is separated into components- different colors of red to violet
Colors show up in that order
Electromagnetic spectrum
An atom absorbed radiation, jumped from lower state to a higher state, it’s going to be emitting- not absorbing, electromagnetic radiation
the energy of an atom is increased when radiation is emitted, coming back down from a higher state, releasing electromagnetic radiation- lse- energy is decreasing
energy of radiation- increases as frequency increases- deadly high energy radiation- right side, low energy radiation- energy increases- high energy as frequency increases- high energy-
low energy- frequency decreases, but wavelength is going to increase
high frequency means high energy
N2 state- electromagnetic radiation at appropriate freqeuncy- emit, release energy absorbed in the first place that made it jump, coming back down- emitting electro magnetic radiation
frequency and wavelength are inversely proportional to each other
above 700- infrared
- don’t see light coming out of bulb
rainbow, see them after rain-
The presence of color in white light is The interaction of light with atoms helped to shape scientistsʼ models of the atom. for the colors we see
in our everyday vision.
• A red shirt appears red because it reflects red light; the shirt absorbs
all of the other colors of light except the red light. Our eyes see only
the reflected light, making the shirt appear red.
The presence of color in white light is responsible for the colors we see
in our everyday vision.
• A red shirt appears red because it reflects red light; the shirt absorbs
all of the other colors of light except the red light. Our eyes see only
the reflected light, making the shirt appear red.
Light travels through space at a constant speed of 2.998 × 108 m/s
low frequency is low energy light, the colors in the rainbow go from lower to higher
