'As this halogen, atomic number 17, kills bacteria, it's used to purify drinking & pool water'
chlorine
HALOGENS: As this halogen, atomic number 17, kills bacteria, its used to purify drinking & pool water
As this halogen, atomic number 17, kills bacteria, it's used to purify drinking & pool water
As this halogen, atomic number 17, kills bacteria, it's used to purify drinking & pool water
HALOGENS
chlorine
HALOGENS