Lab 3 Procedure

The two parts of the lab are:

  1. Investigate isotopes (atoms) of the pretend element Beadium.  Calculating the average masses, relative abundances, and atomic mass of Beadium.
  2. Burn metal salts to observe colored flames for metal salt identification.

Part 1: Investigate isotopes (atoms) of the pretend element Beadium.  Calculating the average masses, relative abundances, and atomic mass of Beadium.

Using a medium-sized beaker, scoop out a random amount of the beads (we will call isotopes or atoms of Beadium) containing the following: blue beads (isotopes), brown beads (isotopes), and clear beads (isotopes).l03_01

Separate the isotopes (blue, brown, clear) of the Beadium into three small beakers.

l03_02 OLYMPUS DIGITAL CAMERA l03_04

On the Data Sheet:

  1. Mass of each isotope: Mass the separate isotopes of all the blue together, all the brown together, and all the clear together. REMEMBER TO SUBTRACT OFF THE MASS OF THE BEAKERS!  Use the unit “amu” (atomic mass unit).
  2. Amount of each isotope: Count all the isotopes separately (how many blue?, how many brown?, how many clear?). 
  3. Average mass of each isotope: Divide the mass of all the blue isotopes(1) by how many of all the blue isotopes you counted(2).  Use “amu”l03_05
  4. Relative abundance of each isotope: Divide how many of all the blue isotopes you counted(2) by how many total count of isotopes you have all together (blue + brown + clear).  l03_06
  5. Relative mass of each isotope: Multiply the average mass of each isotope(3) by the relative abundance of each isotope(4)
  6. Percent abundance of each isotope: Change relative abundance of each isotope(4) into a percent (multiply relative abundance by 100)
  7. Average mass of the element Beadium: add up all three values of relative mass of each isotope(5)

Part 2: Burn metal salts to observe colored flames for metal salt identification.

Safety for this part of lab:

  • Wear safety glasses at all times.
  • Perform all burning and heating in the fume hood.
  • ALWAYS clean up your entire station and any spills made at shared stations.
  • DO NOT deposit broken glassware in trash, place into broken glassware container located near paper towels.

l03_07Set up Bunsen Burner by attaching hose to blue gas outlet inside fume hood and turn the gas knob completely to the left (first turn is very hard).

Using the igniter, light the Bunsen burner and adjust to produce a flame with two blue cones. Be sure to avoid a yellow flame.l03_08

Carefully place the end of a wooden splint that was soaked in the metal salt solution at the top of the inner blue cone. Using the iPad, take a photo of each sample burning. Label the sample on the photo. 

The color given off by the salt is the initial color observed, note: the burning wood will produce a yellow-orange color. 

Inside the fume hood place your burnt wood splints into a beaker of water.

 Repeat with the other metal salt solutions. Be sure to photo or film the colors as precisely as possible.

note: If more observations are needed, dip the clean end of the wooden splint in the solutions for a few minutes and repeat. Otherwise, discard the wooden splints at the end of the experiment.

Final burning: Take a piece of steel wool. Using the iPad take a photo BEFORE and AFTER you burn the steel wool. Make sure you use tongs to hold the burning steel wool. After burning, place in water before throwing into trash. On the photo after indicate if you see the steel wool has changed in color (note: getting darker is a change in color).

FINAL STEP: CLEAN YOUR STATION 

 PUT AWAY ALL EQUIPMENT AND CHEMICALS AND WIPE DOWN YOUR STATION.

Do not leave the lab until the instructor has inspected your clean station.