NOVA: Hunting the Elements Video Questions Worksheet & Puzzles

Science writer and "Tech Guru" David Pogue hosts this special 2-hour episode of NOVA, where he travels the globe exploring the history of the periodic table and the important features of many of the elements. David is an insightful and funny host, and he provides an entertaining and engaging viewing experience. David meets a variety of people involved with the elements, including popular author Theo Gray, who shows David a periodic table "table".

The eight page video worksheet (four pages double sided) consists of 159 multiple-choice questions, and an answer key is included. This may sound like a lot, but I have found that this format enables the students to pay attention to the video while quickly recording their answers. I try to avoid situations where the students are bogged down by writing long responses during a video. I have also broken the worksheet into the sections listed below, which helps with showing the video in installments to match a particular topic. The Zip file download contains files in both PDF and MS Word format. You will need to obtain a DVD of the video or locate an internet site for streaming. I have also included a crossword puzzle and wordsearch featuring terms from the video and the various element names that were mentioned.

I have divided the video worksheet into the following sections (with time stamps) which match those of the video provided by the PBS Internet site:

Quest for Gold

The Sound of Bronze

Atomic Zoom

The Periodic Table

Properties of Elements

Explosively Reactive

The Elements of Life

Elemental Earth

The Rare Earth Elements

Radioactive Dating

Manmade Elements

Other Resources: NOVA: Hunting the Elements

A Google Forms, self-grading quiz of the video questions is available here. (Note: Access to the Google quiz requires an extra charge.)

A Google Doc version of the video questions is available here. (Note: Access to the Google Doc requires an extra charge.)

A PDF version of the video questions formatted for TPT Easel is available here. (Note: Access to the Easel file requires an extra charge.)

A QTI cartridge for the Canvas Learning Management System featuring the video questions is available here. The cartridge will generate a self-grading Canvas quiz. (Note: Access to the Canvas cartridge requires an additional payment.)

The video is available for streaming on the PBS Internet site. (Please make sure that the video is accessible before purchasing this TPT resource.)

NOVA: Hunting the Elements Overview

Author, “Tech Guru”, and writer David Pogue explores the elements of the periodic table in this special 2-hour episode of the PBS series NOVA. David’s sense of humor, and child-like awe at the amazing features of the universe of elements, the building blocks of all regular matter, create an infectious and entertaining episode.

David begins with one of humanity’s first loves, the element gold. We learn that all of the gold ever discovered would fill a single cube just 60-feet on a side. Today, gold is excavated in Nevada at the Cortez Mine where one ton of rock yields just one ounce of gold. Gold is a “noble metal” in that it never rusts or tarnishes. Gold discovered in a Pharaoh’s tomb is just as lustrous and beautiful as it was when it was placed in the tomb thousands of years ago.

Another important metal for early humans was copper. Nearly 7000 years ago, people discovered that copper could be extracted from rocks by heating them in a fire. Copper was easy to work into tools and jewelry. Today, it is a valuable commodity that is traded at the New York Mercantile Exchange where David visits (and attempts to sell scrap copper). The use of copper also ushered in humanity’s bronze age. Bronze is an alloy or mixture of copper and tin, and it could be used to manufacture high quality tools and weapons. The first large-scale empires equipped its soldiers with implements of bronze. Bronze is also used in bell-making, and David visits a modern-day foundry, the Verdin Company in Cincinnati, where large bronze bells are cast. Bronze bells emit a characteristic protracted ring that is valued for church bells and other solemn functions. David also visits a laboratory to examine a sample of bronze using a powerful microscope, which is powerful enough to reveal individual atoms! The microscope shows bronze to be an array or lattice of copper and tin atoms arranged in orderly rows. The microscope enlarges matter 100 million times, which is like examining a bug crawling in grass from a vantage point located 2000 miles above the earth’s surface!

The interior proportions and defining features of atoms are also explored. For example, if an atom of hydrogen were enlarged to be two miles wide, the nucleus would be the size of a golf ball in comparison. Atoms are mostly empty space! The identity of an atom on the periodic table is determined by the number protons in its nucleus. An atom of hydrogen, which is number one on the periodic table, has one proton as its nucleus, and one outer electron. Helium, element number two, has two protons and two electrons. Helium also has two neutrons in its nucleus, which helps to stabilize the protons in the nucleus so that they can come together and stay attached.

The periodic table is further explored with author and chemist Theo Gray, who has worked to popularize the elements with posters, books, and other media. Theo shows David an actual periodic table built with wood, and which contains samples of each possible element. Theo also describes some of the peculiar aspects of the periodic table. For example, why is gold abbreviated as “Au” on the periodic table? Common examples of elements are also highlighted such as bone containing calcium, bismuth in stomach medicine, bromine in drinking soda, and radioactive uranium used as orange glaze in old Fiesta Ware pottery.

The periodic table was first proposed by Russian chemist Dmitri Mendeleev in 1869. David visits St. Petersburg to see Mendeleev’s office and original work spaces. Originally, the mass of hydrogen was used to sort elements by atomic mass. Oxygen, for example, was 16 times more massive than hydrogen. Mendeleev also arranged elements by “family” with elements of similar properties arranged in rows. Gaps in Mendeleev’s chart represented future elements to be discovered, and, when found, fit nicely into the expected areas!

David highlights some of the behavior of groups of elements on the periodic table. For example, elements in group 1 (alkali metals) such as lithium, sodium, and potassium explode in water. Group 2 elements such as calcium and magnesium react with water, but less violently than group 1 elements. The middle groups of the periodic table consist of safe-to-handle metals such as nickel, iron, zinc, and gold. Elements in groups 13-15 inhabit a realm in-between the metals and nonmetals, and they exhibit partial properties of each such as superconductivity. Volatility increases with group 16 and group 17 (the halogens) elements such as chlorine—a poisonous gas used for chemical warfare in World War I—and oxygen, which is important for animal respiration, and is also a corrosive agent that degrades iron and other elements. Group 18, the final column, is the noble gases. These are elements such as helium and argon that do not form compounds with other elements. The behavior of these groups can be explained by the arrangement of outer electrons. In the noble gases, atoms have complete sets of outer electrons, which prevent them from reacting with other elements. In contrast, oxygen is a “notorious electron hound” that is constantly seeking to fill two gaps in its outer electron shell. Oxygen does this by combining with other elements. For example, a molecule of water consists of one oxygen atom combined with two hydrogen atoms. The electrons in hydrogen fulfill oxygen’s need for two more outer electrons.

David explores the dangerous potential of the elements by visiting a lab (EMRI) devoted to the forensic study of explosives used in terrorism, war, and crime. Explosions are observed and filmed in a controlled environment. For example the destruction an old automobile using ANFO, a powerful “fertilizer bomb”, is shown. David found that most common explosives contain oxygen, which rapidly combines with other elements in combustion reactions. These reactions range from relatively slow gunpowder to military grade explosives such as C4. Oxygen atoms in molecules of C4 are packed in close proximity to their reaction partners in order to provide a rapid and destructive result. Forensic technicians are able to measure the elemental composition of bomb residues in order to solve crimes.

David and Christine Thomas, a chemistry professor at Brandeis University, demonstrate that life on earth consists mostly of just a handful of chemical elements, the CHNOPS group. These elements are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. David and Christine purchase the ingredients representing David’s 185 pound body at a hardware store. For carbon, they purchase bags of charcoal. Hydrogen and oxygen are found in bottled water, nitrogen is found in fertilizer, phosphorus in matches (and David’s urine), and sulfur in a rubber automobile tire. Altogether, David’s vital elements cost around $168. David’s body is represented as 97% CHNOPS group elements. The remaining 3% are considered trace elements, and these components can be studied in high tech sports training facilities. David visits a sports medicine facility operated by the Gatorade Corporation, where his sweat is analyzed to determine the amount of zinc, potassium, magnesium, and sodium. Deficiencies in such trace elements can result in cramping in athletes.

David accompanies biologist David Ward as he performs field studies of living bacteria that feed off of hot springs in Yellowstone Park. The samples from Yellowstone are similar to early life on earth dating back to 3-4 billion years. Algae found at Yellowstone are similar to the first microbes to excrete oxygen. The early earth originally lacked an oxygen atmosphere, and it has been shown that early bacterial life on earth generated oxygen by photosynthesis; as a result, earth’s oxygen-rich atmosphere is an artifact of life, and the evolution of life on earth changed our planet in significant ways. This early oxygen-generating life is known as cyanobacteria, or blue-green algae. Today, about one-half of the oxygen we breathe is generated by microbes.

The original elements in the universe, hydrogen and some helium, were forged in the first three minutes after the Big Bang, the origin of the universe about 13.8 billion years ago. When you drink a glass of water, you are consuming atoms of hydrogen in the water that were made at the Big Bang! Today, we know that most of the chemical elements after hydrogen on the periodic table were made in ancient stars that lived and died before our earth and sun formed. An astounding discovery of modern science is that our earth and bodies are made of atoms that were generated in ancient stars! As American astronomer and science popularizer Carl Sagan said, we are made of “star stuff”. Most stars fuse hydrogen into helium, a process known as fusion. (In the video, David visits the National Ignition Facility, where scientists are recreating this process on earth in the hope of eventually using it as a source of nearly free, limitless energy.) Eventually, as stars age, they begin to synthesize heavier elements such as carbon, silicon, oxygen, etc. all the way up to iron. At iron, stars reach a point where no more energy can be generated by fusion and the star collapses, creating a titanic explosion known as a supernova. The intense heat of these explosions is then able to generate elements heavier than iron such as gold and platinum. The precious metals in your jewelry were made in ancient exploding stars!

Silicon, the second most abundant element in the earth’s crust (after oxygen), is a member of the semiconductors. According to David, the semiconductors are smallest neighborhood of the periodic table. Silicon has been used for millennia in glass, and in the modern world as the components of computers. David visits the Corning glass company in New York to document some amazing new applications for glass. Corning is able to make strong, flexible glass by adding metal atoms into the mix. Corning also makes “gorilla glass”, a super-strong glass used for iPhone screens.

The rare earth elements occupy an entire row near the bottom of the periodic table. Elements from this group have important applications in modern technology. Neodymium, for example, is added to iron to create the powerfully strong magnets that are used in cell phones, hybrid cars, wind turbines, and tiny earbuds. Only one rare earth mine exists in the United States, and the majority of rare earth minerals (98%) are imported from China.

An interesting application of neodymium and other rare earth minerals is in making shark-repelling hooks. Many sharks are accidently caught by commercial fisherman, and ways to prevent these unfortunate occurrences would be beneficial to the shark population. David meets marine biologist Patrick Rice who demonstrates the repelling effects of strong magnets on captive sharks. The sharks appear to be able to sense strong magnetic fields, and Patrick attempted to use magnets with fishhooks but was stymied when the magnets caught the hooks. Patrick later found that nonmagnetic samples of the rare earth element samarium also had a repelling effect when placed in the water close to a shark. It appears that the samarium delivers a mild shock to the shark through the ion-carrying ability of salt water. Patrick detailed that in one application of samarium with 46,000 fish hooks, the amount of sharks accidently caught dropped by 27%.

Isotopes are forms of an element that contains extra neutrons in the nucleus making a slightly heavier, sometimes unstable atom. The most famous isotope is carbon-14 which is used in dating old, once-living matter. “Normal” carbon is named carbon-12. An atom of carbon-12 contains six protons and six neutrons (plus six electrons). Adding protons and neutrons provides the “-12” suffix. Carbon is also found in small amounts as the isotopes carbon-13, which contains one extra neutron, and carbon-14, which contains two extra neutrons. These varieties of carbon are still considered to be the element carbon, and the classification of elements is based solely upon the number of protons in the nucleus.

Carbon-14 is unstable and radioactive. One of the extra neutrons in a carbon-14 can suddenly change into a proton, releasing an electron and changing the atom into the next element in the periodic table, nitrogen. Scientists know how long half of the atoms in a sample of carbon-14 will take to decay into nitrogen. This value, termed half-life, is around 6000 years for carbon-14. By measuring the amount of carbon-14 in a sample of once living matter (wood, for example), the time since death can be determined by comparing this amount to the amount of carbon-12 present in the sample. Carbon-14 dating can be used to date material 40,000 years old or less. In the video, David meets environmental scientist Scott Stines who uses carbon-14 dating to determine the ages of trees near Mono Lake in Yosemite, California. Scott uses the time since death for these trees to determine the average length of droughts in California.

After and including element 84, polonium, the rest of the periodic table elements are radioactive, meaning that these atoms will eventually decay into different elements. Starting in the early to mid 20th century, experiments were performed in which neutrons were used to bombard elements, splitting the nucleus into new elements. This fission reaction formed the basis for the atomic weapons used by the United States against Japan during World War II. David visits the National Museum of Nuclear Science and History in Albuquerque, where he examines replicas of the Little Boy and Fat Man, the two nuclear bombs of WW2. The fissile material used in Little Boy was uranium-235, a rare isotope of uranium. Extracting significant amounts of uranium-235 was difficult, so the atomic scientists used easier to obtain plutonium for the Fat Man weapon.

Originally element 92, uranium, was thought to be the last element of the periodic table. Experiments with nuclei led to the discovery of the first man-made element plutonium by Glenn Seaborg in 1940. Work expanding the periodic table continues. Chemist Ken Moody has performed experiments to discover six new man-made elements; the only ‘hitch” is that the elements decay rapidly, only lasting for a few seconds at most. Ken hopes to eventually find an “island of stability” on the periodic table, a region containing very heavy, but stable new elements that could be used by future civilization.