Contents
Key Stage 2
Meaning
Key Stage 3
Meaning
Chlorine is a Group 7 element, on the Periodic Table, with an atomic number of 17.
About Chlorine
- Chlorine has the chemical formula Cl2.
- Chlorine as 17 protons and 18 neutrons in its nucleus giving it an Atomic Number of 17and an atomic mass of 35.
- Chlorine is a more reactive Halogen than Bromine but less reactive than Fluorine.
- Chlorine reacts strongly with Hydrogen to produce Hydrogen Chloride which dissolves in water to produce Hydrochloric Acid.
- Chlorine is a strong bleaching agent.
- Chlorine kills bacteria.
- Chlorine is a pale green coloured gas at room temperature.
- An atom of Chlorine is missing one electron from having a full outer shell.
- Chlorine ions gain 1 electron to get a full outer shell and become negatively charged.
Key Stage 4
Meaning
Chlorine is a Group 2 element, on the Periodic Table, with 17 protons in the nucleus.
About Chlorine
- Chlorine has the chemical formula Cl2.
- There are two stable isotopes of Chlorine, one with 18 neutrons and the other with 20 neutrons. They occur in a ratio of roughly 3:1 so the atomic mass of Chlorine is 35.5.
- Chlorine is the most reactive Halogen.
- Chlorine reacts strongly with Hydrogen to produce Hydrogen Chloride which dissolves in water to produce Hydrochloric Acid.
- Chlorine is a strong bleaching agent.
- Chlorine kills bacteria.
- Chlorine is a pale green coloured gas at standard temperature and pressure.
- An atom of Chlorine has only 2 electrons in its outer shell.
- Chlorine ions gain 1 electron to get a full outer shell and become negatively charged.
Testing For Chlorine
- Collect the gas in a test tube.
- Place a piece of litmus paper over the mouth of the test tube.
- If the litmus paper is bleached white then the gas is Chlorine or Fluorine.