NOVA:Hunting the Elements

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Terms in this set (...)

There are ________ unique substances (elements) arranged on an amazing chart that reveals their hidden secrets to anyone who knows how to read it.
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All the gold ever mined would fit into a single cube about _______ feet on a side.
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Three-quarters of the elements are ________________.
metals
How an atom reacts chemically depends on how willing it is to share _________________ with others.
electrons
How much would a 60 pound block of gold be worth in dollars? $_________________________
1 and a 1/2 million dollars
List two things copper is used for:
a.
b.
a) wire
b) plumbing
When copper is combined with another element, __________, it makes bronze, the first manmade
metal alloy.
tin
The number of ________________ determines what kind of element the atom is.
protons
The number of protons is called the atomic ________________ and it's the fundamental organizing
principle of every table of the elements.
number
Metals are shiny, malleable materials that conduct ____________________________.
electricity
Most people think of _________________ as white and chalky, but it's actually a silver, shiny metal.
calcium
. Fiesta® ware bowls, like this one from the 1930s, gets its orange color from _________________ , and
it's actually dangerously radioactive.
uranium
The table organizes the elements by atomic number, that is, the number of protons in each atom, yet
the table's creator - a 19th
-centruy Russian chemistry professor, named Dmitri ___________________,
knew nothing about protons or atomic numbers.
mendeleev
The group that fits neatly onto the end of the table, the _____________ __________, are unwilling to
mix with the other elements, to react with them.
noble gasses
Protons may determine the identity of an element, but _________________ rule its reactivity.
electrons
An atom with _______ electrons in its outer shell makes one happy, satisfied atom.
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The column just before the stable noble gases are called the _________________. They have an outer
shell that needs just one more electron to be full.
halogens
The ______________ metals are the first column. Each of them has full shells, plus one extra electron
sitting in a new, outer shell
alkali
The ion chromatograph looks for positively or negatively charged molecules, called __________, in the
residue, fragments of the original chemical explosive.
cation exchange
. Every time atoms form a new bond, the reaction releases _______________.
energy
How do you speed up a fire to create an explosion? You regulate the amount of ________________
and how closely it's packed together with other elements.
oxygen
The oxygen that powers all those explosions makes up ______% of our atmosphere. It's the most
abundant element in the earth's crust.
21%
What six elements make life possible?
C,H,N,O,P,S
List two ways that carbon is found in its pure form:
graphite, graphene
Your body composition is about _______% carbon and _______% nitrogen.
18% and 3%
. Hydrogen and oxygen can actually be separated from water using a little bit of ___________________.
electricity
. In a person's body, there's _______% oxygen.
65%
. Phosphorus is actually involved in something really important called _________, which is the molecule
that all cells use for energy.
ATP
Phosphorus makes up about _______% of the human body. It was the first element isolated from a
living creature.
1%
. Altogether just those six CHNOPS elements make up 97% of the weight of his body, but what about the
other 3%? Those are what's called the _________________ elements.
T,R,A,C,E
. _____________ is important for energy metabolism.
Magnesium
____________________ is an important part of nervous system function.
Sodium
. In total, the human body uses more than _______ elements in ways and quantities that are unique to
us.
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As the planet cooled, another ancient microorganism evolved and changed everything. They are called
cyanobacteria, but we know them as _____________________________. They found a way to get
their energy from light and water, releasing oxygen as a byproduct, just like modern plants do.
Blue-Green Algae
Around 90% of all the atoms in the universe are ________________, and they were all made by the Big
Bang, more than 13 billion years ago.
Hydrogen
Stars like our own sun are constantly turning hydrogen atoms into element number two: helium. It's a
process called ________________.
Fusion
By the time it's fusing iron, a star is in its death throes. It begins to collapse, and if it's massive enough,
that collapse leads to a powerful explosion called a ______________________.
Supernova
This element, with 14 protons and 14 electrons, is the 2nd most abundant element in the earth's rocky
crust and is a member of one of the smallest neighborhoods on the table: the semiconductors.
__________________________
Silicon
Glass all starts with ordinary ___________, which is made of a combination of silicon and oxygen.
Sand
Glassmakers have learned how to precisely place minute amounts of ___________ atoms like sodium,
potassium, and aluminum among the silicon atoms. The result is hard, yet flexible and scratchresistant.
Metal
Switches made out of semiconductors made computers possible, but lately when it comes to high tech,
there's a new family on the block, the __________ _____________, 15 elements located near the
bottom of the table.
Rare Earths
List three uses of the rare earth metal neodymium.
Magnets, Cars, Earbuds
Where do the majority (98%) of rare earth minerals come from in the world?
China
. ___________ makes magnets, but adding neodymium makes magnets on steroids.
Iron
They accidently discovered that the strong neodymium magnets (and other rare earth elements) can
actually repel _____________.
Sharks
Scientists now know that most elements come in more than one version. The different versions are
called _____________________. The different between them is the number of neutrons in the
nucleus.
Isotopes
To determine how long ago droughts occurred, Scott is using __________________ to date the trees
because it is unstable and the atoms begin to deteriorate over time in a process called radioactive
decay.
Carbon 14
. Carbon-14 can be sued to date samples up to __________________ years old.
500
. At the bottom of the periodic table, beginning with number 84, polonium, all of the elements and their
isotopes are ______________________.
Radioactive
Before the nuclear age, uranium was thought to be the end of the periodic table, but in the last 70
years, scientists have left nature behind and created _______ new elements.
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