1. Diatomic = “di” + “atomic” “di” = Greek prefix; means “two”
QUESTION:
Which of these elements naturally occurs as a diatomic gas under ordinary conditions? A. bromine, B. iodine, C. mercury, D. chlorine
Diatomic = “di” + “atomic”
“di” = Greek prefix; means “two”
Diatomic molecule: made up of two atoms
There are only seven elements known to naturally exist as diatomic molecules under ordinary conditions. H2, N2, O2, F2, Cl2, Br2, I2
SCRIPT:
Which of these naturally occurs as a diatomic gas under ordinary conditions? A. bromine, B. iodine, C. mercury, D. chlorine
PAUSE
The term diatomic comes form the greek prefix di… and atomic
CLICK
Di… means two.
Therefore, a diatomic molecule is a molecule that is made up of two atoms.
CLICK There are only seven elements known to naturally exist as diatomic molecules under ordinary conditions.
HIGHLIGHT each element as they are called.
Hydrogen… nitrogen.. Oxygen… fluorine… chlorine…bromine… and iodine
Note that when we are referring to these elements as they occur in nature, we indicate a subscript of two next to the symbol
for the element. HIGHLIGHT subscripts
Obviously, … mercury is not the correct answer.
CROSS OUT mercury
The question is, … which of the remaining three choices… bromine, iodine, and chlorine… is gaseous under ordinary conditions?
The answer is chlorine. Bromine is a liquid and iodine is a solid.
It might help you to remember these elements by looking at where they are located in the periodic table.
CONTINUED ON NEXT SLIDE

2. Gaseous, diatomic Liquid, diatomic Solid, diatomic Here they are…
Hydrogen
CLICK nitrogen
CLICK
Oxygen
Chlorine
Hydrogen, nitrogen, oxygen, fluorine, and chlorine are all gaseous under ordinary conditions
Bromine is a liquid under ordinary conditions.
CLICK CLICK
And iodine is a solid under ordinary conditions.
PAUSE
CLICK PAUSE END RECORDING
Gaseous, diatomic
Liquid, diatomic
Solid, diatomic

3. Video ID: © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Narrator: Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08