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“To think is to practice
brain chemistry.”
Deepak Chopra
All About Subatomic Particles How to find the number of protons,
neutrons, and electrons that atoms have, as well as finding the
number of valence electrons
History
"Chemistry is a branch of science
that has been around for a long time. In fact, chemistry is known to
date back to as far as the prehistoric times. Due to the amount of
time chemistry takes up on the timeline, the science is split into
four general chronological categories. The four categories are:
prehistoric times - beginning of the Christian era (black magic),
beginning of the Christian era - end of 17th century (alchemy), end
of 17th century - mid 19th century (traditional chemistry) and mid
19th century - present (modern chemistry).
Source:
History of Chemistry
