1. 118
   90
2. 14
   56

Out of the 118 elements found on the periodic table, 90 of them can be found existing in nature. The other 28 elements are man-made, and they were inspired by technetium, the first man-made element.

1. He
   Ho
2. H
   Hs

After hydrogen (H), helium is the second most common element in the known universe. Tasteless, colorless and odorless, helium (He) is used for more than giving you a wacky voice at parties. It's one of the most unique elements on the periodic table.

1. Iron
   Silver
2. Lithium
   Fluorine

If you were working with the element denoted as "Fe" on the periodic table, you would be working with iron. Iron is the fourth most abundant element found in the earth's crust, and it's the sixth most common element in the entire universe.

1. Jupiter
   Venus
2. Mars
   Uranus

We haven't yet been able to collect samples from Venus, Jupiter or Uranus, but we do know that the elements on Mars are identical to those found on Earth. Some of the elements found on Mars' crust are magnesium, iron and calcium.

1. Calcium
   Manganese
2. Aluminum
   Silicon

Milk does do a body good, and calcium in the reason. It's not often found in its pure form, but versions of it, like calcium carbonate, can be found in the oceans and many rocks, like limestone.

1. Niobium
   Nobelium
2. Nitrogen
   Nickel

Nitrogen's atomic weight of 7 puts it right beside oxygen on the periodic table. When you breathe in, you inhale both elements, but nitrogen makes up the larger percentage.

1. Gallium
   Gadolinium
2. Gold
   Germanium

When Mendeleev created the periodic table, he predicted that gallium — an element similar to aluminum— would soon be discovered. Only six years later, he was proven correct when a French scientist named Lecoq de Boisbaudran discovered it in 1875.

1. Gold
   Silver
2. Iron
   Copper

Gold, copper and silver are all part of Group 11 and casually called coin metals because of their use in making currency. Along with iron, osmium and hassium, iron belongs to Group 8.

1. Solitaire
   Rummy
2. Gin
   Euchre

A huge gaming enthusiast, University of St. Petersburg professor Dmitri Mendeleev decided to sort each element by its atomic weight. He then sorted them by "suit" with similar elements making up each column — just like the game of solitaire.

1. Angola
   Albania
2. Argentina
   Algeria

Every year, Argentina mines over 10 million pounds of silver. Known as The Land of Silver, it's the largest producer of the metal in the world. It only makes sense that it would have been named after the element Ag, or Argentum.

1. Iron
   Neptunium
2. Uranium
   Sulfur

Symbolized as "U" on the periodic table, uranium is the heaviest element on earth. Its man-made counterpart, ununoctium, carries an atomic weight of 118. When the element with the atomic weight of 120 is discovered, ununoctium will have to take a back seat.

1. Hydrogen
   Oxygen
2. Carbon
   Helium

Both liquid and solid forms of oxygen appear as a pale blue, but it can come in other colors, too. It's the most abundant element in the human body, and it's the third most common element found in the entire universe.

1. Argon
   Americium
2. Oxygen
   Palladium

When argon was discovered in 1894, Mendeleev decided to ignore it because it didn't fit into his version of the periodic table. Argon's name is taken from the Greek word "argos." Argos means lazy or idle, and the element's slow, nonreactive behavior makes it a natural fit.

1. They disappear.
   They increase in number.
2. They mutate with other numbers.
   They decrease in number.

When going from left to right on the periodic table, you'll notice that the number of valence electrons increases. Likewise, you'll notice that energy levels increase as you scan from top to bottom.

1. Helium
   Hydrogen
2. Xenon
   Radon

Found in the upper left-hand corner of the periodic table, you'll see the element named hydrogen. Denoted with the letter H, hydrogen makes up about 10% of the body of any living organism.

1. G
   P
2. K
   J

In countries like Norway and Poland, iodine is often called jod. You won't see the letter "J" on the periodic table, though. Iodine is still listed by its IUPAC symbol "I." "J" is the only letter of the alphabet left out.

1. Reactive
2. Noble

Along with helium, xenon, radon and radon, these elements are called noble gases. The noble gases make up group 18 on the periodic table, and they're known for being relatively unreactive with other elements.

1. True
2. False

In 1869, a Russian chemist named Dmitri Mendeleev sorted the elements into the rows and columns that we know today. Using this method, he was able to predict the discovery of many new elements.

1. Atom shell
   Cell shell
2. Elemental shell
   Valence shell

The part of an atom where the determining electrons are found is called the valence shell. The electrons found in the valence shell determine the chemical property and allow them to be classified as the correct element.

1. Electrons
2. Protons

Usually represented by the symbol "Z," the atomic number identifies elements using the number of protons found in the nucleus. Sometimes called the proton number, it gives each element a unique signature.

1. Uranium
   Francium
2. Argentum
   Cobalt

Francium has an atomic number of 87, and you can find it noted on the periodic table with the abbreviation "Fr." There are only a couple of ounces of it on earth, and it has no real use outside of scientific research.

1. Atomic number
   Weight number
2. Mass number
   Proton number

Each of the elements on the periodic table has four pieces of information: the atomic number, the element's symbol, the element's name and the mass number. The mass number, found at the bottom, indicates the number of protons and neutrons found in that element's nucleus.

1. Nonmetals
   Metals
2. Isotopes
   Metalloids

On the left side of the staircase, you will find the elements that belong to the metal family. To the right, you'll find metalloids that can perform as either metal or nonmetal elements.

1. Inert gasses
   Metals
2. Noble gasses
   Organic

Out of the 118 elements on the periodic table, at least 91 of them are metals. Wihile some of them appear in both the metallic and non-metallic categories, those that are not considered metals are called metalloids.

1. Magnesium
   Neon
2. Bohrium
   Phosphorus

Both magnesium and phosphorus are considered highly reactive, but only phosphorus glows in the dark. Because phosphorus catches fire easily, it is often used on the tips of matches. It's phosphorus, not sulfur, that gives matches their stinky smell.

1. Alkali
2. Alkaloid

Found at the bottom left corner of the periodic table, the most active metals are alkali metals. The most reactive of them are helium, sodium and potassium — all of which react with water.

1. Does not exist naturally
   Has yet to be discovered
2. Weighs less than other elements
   Cannot combine with other elements

Elements with an atomic number of 92 or higher are created when parts of elements combine with other elements. Any atomic weight above that point is not considered a naturally occurring element.

1. 18
   7
2. 6
   14

Simply put, each of the 18 columns in the periodic table is made up of similar elements. Each group — such as inert or noble gases — is put together so that chemists can more accurately predict how an element may react in different situations.

1. Argon
   Arsenic
2. Helium
   Carbon

Carbon takes its name from "carbo," the Latin word for coal. Making up .032% of the earth's crust, carbon can be found in many forms, including diamonds, graphite and lithium-ion batteries.

1. Right
2. Wrong

Mendeleev assumed that all the elements were unchanging forms, but the study of radioactivity proved him wrong. Elements like uranium break down into other elements. Uranium's last breakdown is lead.

1. None
   Four
2. Two
   Eight

In their natural states, there are only two of the elements that are found in liquid form. Both mercury (Hg) and bromine (Br) are liquid at room temperature, but there are others that will melt when superheated.

1. Go
   K
2. Au
   Ga

When looking at the periodic table, you'll see a bunch of abbreviations that represent the elements. Some elements are easy to identify, but others, like gold, are a little harder. The correct abbreviation for it is Au — it's short for gold's Latin name, aurum.

1. Period
   Group
2. Column
   Sorting

The name "periodic table" comes from the horizontal rows that are called periods. Of the eight total periods, the first row has the least with only two elements. The sixth row has the most with 11.

1. The staircase
   The division
2. Elemental line
   The metallic line

Over the course of history, the line that separates metal and nonmetal elements has been called many names. Most commonly called the staircase, you'll sometimes hear it called the amphoteric line and the metal-nonmetal line.

1. Isaac Newton
   Benjamin Franklin
2. Dmitri Mendeleev
   Albert Einstein

Because Dmitri Mendeleev was running out of time for a publishing deadline, he opted to assign atomic weights to each element. Rather than describing each element, giving each an atomic weight provided a shortcut for grouping them together.