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Big History Project
Course: Big History Project > Unit 3
Lesson 3: Way of Knowing: Stars and Elements | 3.2WATCH: Intro to Chemistry
Anne McNeil introduces how chemistry, the central science, unravels the mysteries of matter, and shows us how matter has changed over time. From understanding the stretchy nature of rubber bands to predicting the properties of caffeine, chemistry is key. Today's chemists, armed with advanced techniques, innovate in diverse fields, from astrochemistry to biochemistry, paving the way for future breakthroughs. Created by Big History Project.
Want to join the conversation?
- I heard that Ozone is oxygen that grabbed on to more hydrogen and that it can turn back into oxygen. Is this true?(13 votes)
- Short answer Yes. The details? Ozone is called O3, with the 3 in subscript, and Oxygen is called O2, again with the two in subscript, but I think that's saying that Ozone is Oxygen with an extra O, it has something to do with Oxygen, or O wanting to bond or wanting two electrons and that's why the H clings to it, and makes H2O, and why it bonds to itself sharing it's own desire to have two more electrons with another O, I have no Idea why they want these other electrons, or what they're goina do with them it they get them, but there is some kind of attraction there. I may have to go back and watch the videos in the chemistry section. Hope this helps, T.S.(13 votes)
- What kind of chemist is she?(0 votes)
- Her profile page on the University of Michigan College of Literature, Science, and the Arts website states she is “Professor of Chemistry; Macromolecular Science and Engineering”, and she is involved in “sustainable polymers”. So she is a Macromolecular Chemist.(1 vote)
- What is the difference between computational and practical research?(0 votes)
- Computational research makes inferences and comes to conclusions based on data which come from various sources.
Practical research begins with materials and involves manipulating those materials individually and in combination to come to inferences and conclusions.
Computational research requires access to data. Practical research requires access to a lab.(2 votes)
Video transcript
Hi. My name is Anne McNeil, and I'm an assistant
professor here at the University of Michigan, where I study the chemistry
of organic materials. When I was growing up,
I was interested in what everything was
made of and how it worked. And before the Internet, I had to find answers
to these questions in books. I even got my first
job at a library so I could have
access to more books. And I didn't really have a
favorite subject at the time because I liked
all aspects of science. And it wasn't
until I got to college, when my professor was explaining how a rubber band gets its
stretchy characteristics based on how the
atoms are connected within that structure of rubber, that I realized that just about
everything can be explained if you understand the atoms
that make up that material as well as how they're
connected to each other. And it was then that I decided
I wanted to be a chemist. So, chemistry is broadly
defined as the study of matter, and the goal is to understand
the structure of matter and its composition, so understanding what
elements make up that matter and how they're
connected to each other. And then chemists can use
that information about structure and composition to predict and
understand its properties. So, I'm showing you here a three-dimensional
model of caffeine and we can use our
understanding of the structure of caffeine to understand
how it interacts with our body. Another example you might
be familiar with is ozone. As early as 1865,
chemists had discovered that ozone consisted
of three oxygen atoms. But it wasn't until much later that they discovered
that the structure was actually
this bent structure. And based on our understanding
of this bent structure, we can now understand
some of the properties of ozone like its ability to absorb the skin-damaging
UV radiation from the sun but also some of its
negative properties, like its reactivity
with nitrogen oxides to generate smog. So, just as the chemistry
of the Universe has evolved from simple hydrogen and helium to now the complex molecules of
DNA that are within your body, so has our study of chemistry. So, in the old days,
people were very limited on the techniques to determine
both structure and composition. And instead of having
some advanced techniques, they often resorted
to tasting compounds and classifying them
as bitter or sweet. Now, fortunately today, we
don't taste compounds anymore. We have a number of techniques
we can use to determine both structure and composition. So, for example, if we have a
crystal of caffeine, we can look at how
X-rays are scattered as they pass
through that crystal and use that information
to identify both the atoms as well as their connectivity. We can also inject
a molecule of caffeine into a mass spectrometer and get the mass
of the molecule. And we can use
various forms of spectroscopy, which involves the absorption
and emission of light, to identify functional groups like a carbon-oxygen
double bond. And so using all
of these techniques, we are no longer limited in determining both
structure and composition. And as a result, you'd be
amazed to see many of the innovations that are
coming out of labs today. So, for example, we can
completely replace glass bottles with plastic bottles
that are easier to recycle and can even biodegrade. So, chemistry is often referred
to as a central science because it plays a role in so
many of the other sciences. So, for example,
an astrochemist is involved in the search for life on Mars by looking for the
distinct spectroscopic features of water on that surface. And geochemists are involved in telling the
history of the earth by looking at the changes in the atomic composition
of rocks over time. And biochemists are
involved with developing various drug molecules
to help treat and cure diseases. So, as chemistry
is so essential to all these other sciences, chemists will play a role
in the future innovations in all of these fields. So, for example, chemical biologists
are now trying to design drugs that are specific
for you based on your DNA, and analytical chemists are
trying to develop microchips that they can install and
non-invasively monitor your health and report
back to your doctor without stepping foot
in an office. And materials chemists
are developing materials that will capture
sunlight efficiently and convert that
directly into electricity so that we can reduce
our reliance on fossil fuels. And synthetic chemists
are developing catalysts that they can use to convert
a greenhouse gas like CO2 into a useful fuel
that we can burn. And so, if you today
ask a chemist what they do, you'll often hear them say,
"I'm a something chemist. "I'm a materials chemist
or a physical chemist, or an analytical chemist." Chemists are everywhere,
and they're contributing to all of these different
fields of science.