This is a great question! Most people who have
encountered liquid bleach or bleaching powder know
that bleach will remove colors (also called
pigments) from fabrics and other materials as
well, as kill bacteria and other microorganisms;
however, not everyone knows how this process
works, or, to put it more technically, the
mechanism through which bleach accomplishes these
To best answer this question, we're going to
have to think about some chemistry. First of all,
pigments are made of organic molecules
containing segments called "chromophores"
which, when illuminated with white light, will
absorb some of the colors and reflect other
colors. The colors that are reflected are the
colors that we perceive when we view an object
with our naked eyes. The properties and chemical
structures of chromophores that let them absorb
light are very specific, and tend to be very
"chemically active," or able to participate
in chemical reactions very easily.
Both liquid bleach (a solution of sodium
hypochlorite, NaClO) and bleach powder (solid
calcium hypochlorite, Ca(ClO)2) are
also very chemically active and work by
reacting with chromophores in pigments and
destroying the structures that allow the
chromophores to absorb light. If the
chromophores can't absorb light anymore, then they
reflect all of the colors of white light and the
material appears white to our eyes.
Bleach works somewhat similarly when it kills
microorganisms. Bleach either unravels the
delicate protein structures that bacteria or other
pathogens use to live or disrupts the cell
membranes of the bacteria, causing them to
pop, quite like a balloon!
Thanks for being so curious! I hope my answer
helped you better understand how bleach works.
Keep the questions coming!
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