Bellwork 1) Get out electron configuration worksheet, atomic spectra worksheet (half paper), and stamp sheet. 2) Get out planner and write down homework 3) Draw the orbital diagram, write the full electron configuration and noble gas configuration for Y-1

Jumping Electrons, Light, and Spectra How properties of light can help us identify elements

As metals get heated… If you put different metals in flame, the metal will glow different colors. For example, this metal is glowing red. Why? The flame adds more energy to the atom. This causes the valence electrons to get excited & jump. Excited valence electrons will eventually calm down. When they do, they give off a photon of light. By studying the photons, we can identify the element that produced them

Radiation & Light Many objects in our universe give off different types of radiation. Radiation is a way to transfer energy in either particles or waves There are 7 types of electromagnetic radiation (EMR): Radiowaves (power our radios) microwaves infrared (remote controls, body heat) visible light (light bulbs, photons) ultraviolet (sun, tanning beds) x-rays (medicine, black holes) gamma rays (high level radioactivity)

Short Wavelength Long Wavelength High Energy Low Energy

Ground State Electrons Excited State Electrons Electron States Ground State Electrons Excited State Electrons Ground state electrons are ones where electrons are in the lowest energy level. This is the normal e- configurations that we have been writing Electrons that absorb enough energy will jump from the configuration they are supposed to be at to a higher energy level, called the excited state. Quanta is the minimum amount of energy needed to jump. Quanta is the energy cost. The more levels the electron jumps, the higher the quanta When the electron calms down, the electron will jump back to its ground state and will release light called a photon. The photon of light can be studied to positively identify the element that produced it.

Excited State The light of a photon can be analyzed to show a spectrum, or pattern of colored lines Each element will give a specific pattern of spectrum colors. This pattern or spectrum, is like a DNA fingerprint for the element. In the picture, as electrons jump back, they are giving off photons of different energy levels, which we interpret as different colors Red is low energy Violet is high energy The distance between the 2 energy levels represent a quanta, or the minimum amount of energy needed for an electron to jump. The more levels the electron jumps, the higher energy photon is released.

Emission Spectra The pattern of colored lines at specific wavelengths that photons give off is called the atomic emission spectrum. An atomic emission spectrum is like a fingerprint of the element being examined and can be used to identify that element. Scientists use this method to to identify what elements are present in chemical samples, stars and planets.

Examples of Spectra

The Sun Hydrogen Helium Mercury Uranium

Station Video https://www.youtube.com/watch?v=NSAgLvKOPLQ