elements

• April 20th 2008, 10:05 PM
Seza<3
elements
Do you guys know any of these?

- What is the difference between nitrogen in the atmosphere and liquid nitrogen?
- Why wld turning liquid nitrogen into gas in a closed container produce a lot of pressure?
- An atom of sodium has 11 protons and 11 electrons. How does an ion of sodium differ from this?
- The chloride ion has 17 protons and 18 electrons. What is the charge on the chloride ion? How does this differ from the chlorine atom?
- Why will salty water conduct an electric current when pure water will not?
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• April 20th 2008, 10:08 PM
Jhevon
Quote:

Originally Posted by Seza<3
What is the difference between nitrogen in the atmosphere and liquid nitrogen? Anyone know?

nitrogen in the atmosphere is a gas? (Rofl)
• April 21st 2008, 12:52 AM
earboth
Quote:

Originally Posted by Seza<3
Do you guys know any of these?

- What is the difference between nitrogen in the atmosphere and liquid nitrogen? Nitrogen in the atmosphere is allways a molcule $N_2$ and - as Jhevon pointed out - it is a gas.
- Why wld turning liquid nitrogen into gas in a closed container produce a lot of pressure? One volume unit of liquid nitrogen will change into approximately 1500 volume units of gas. If there isn't the space to perform this change the pressure will increase.
- An atom of sodium has 11 protons and 11 electrons. How does an ion of sodium differ from this? Na has only one electron on the outer sphere (the 3rd) where the electrons are located. With an ion this electron on the 3rd sphere is missing, so the Na-ion is electrically charged positiv.
- The chloride ion has 17 protons and 18 electrons. What is the charge on the chloride ion? How does this differ from the chlorine atom? Because there are more electrons than protons the chlorine ion is charged negative.
-Why will salty water conduct an electric current when pure water will not? If salt is dissolved in water the molecule NaCl dissociates (? that's the expression used in German to describe the process that the molecule is split into 2 ions) into $Na^+$ and $Cl^-$. These ions transport the electric charges - and the transport of electric charges is called electric current. (I guess you have seen that the ions must be insulated against each other. This is done by the water molecules which are build as electrical dipoles.)

This is only guessing because it is a long time ago that I've done a little bit chemistry.