Chlorine - Cl
- 17 protons, 17 electrons, and 18 neutrons.
- Discovered in 1774 by Carl William Scheele in Sweden.
- The original name was "chloros" meaning pale green in Greek.
- Scheele obtained it through a reaction of the mineral pyrolusite with hydrochloric acid, thinking oxygen gas would be produced.
- Sir Humphry Davy later confirmed chlorine to be an element in 1810, and he also named it.
Properties of chlorine and some uses:
- Electronegativity- 3
- Pure element has the form of a diatomic green gas and 2.5 times heavier than air.
- Very strong, suffocating odor and poisonous.
- In solid and liquid form it's a bleaching and disinfecting agent.
- Chlorine is very important for water purification and mustard gas.
Compounds with chlorine:
- Aluminum chlorohydrate- antipersperiants
- Sodium chloride- table salt
- Hydrogen chloride- when mixed with H20, hydrochloric acid forms.
Powder aluminum chlorohydrate
- NaCl (aka table salt)
- 1:1 ratio
- Synthesis reaction
Group 7a (17)
- Group 17 is the halogens, they only need 1 electron to be stable so they are very reactive.
- Halogens are generally poisonous, all with a different levels of toxicity.
- They are poor conductors of heat and electricity.
- They can exist usually in solids, liquids, and gases.
- Halogens can separate and combine with surrounding elements and create compounds.
Chlorine and Milk