Periodic Table of the Elements


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Periodic Table of the Elements

The classic Periodic Table organizes the chemical elements according to the number of protons that each has in its atomic nucleus.

Credit: Karl Tate, Livescience.com contributor

The Periodic Table of the Elements arranges all of the known elements in an informative array. Elements are arranged in order of increasing atomic number. Order generally coincides with increasing atomic mass.

The different rows of elements are called periods. The period number of an element signifies the highest energy level an electron in that element occupies (in the unexcited state), according to the Los Alamos National Laboratory. The number of electrons in a period increases as one moves down the periodic table; therefore, as the energy level of the atom increases, the number of energy sub-levels per energy level increases.

Elements that lie in the same column on the periodic table (called a “group”) have identical valance electron configurations and consequently behave in a similar fashion chemically. For instance, all the group 18 elements are inert gases. [Related: How Are the Elements Grouped?]

The periodic table contains an enormous amount of important information:

Atomic Number: The number of protons in an atom defines what element it is. For example, carbon atoms have six protons, hydrogen atoms have one, and oxygen atoms have eight. The number of protons in an atom is referred to as the atomic number of that element. The number of protons in an atom also determines the chemical behavior of the element.

Element Symbol: The element symbol is one, two or three letters chosen to represent an element (“H” for hydrogen, “Kr” for krypton, “Uup” for Ununpentium, etc.). These symbols are used internationally.

Atomic Weight: The standard atomic weight is the average mass of an element in atomic mass units (“amu”). Though individual atoms always have an integer number of atomic mass units, the atomic mass on the periodic table is stated as a decimal number because it is an average of the various isotopes of an element. The average number of neutrons for an element can be found by subtracting the number of protons (atomic number) from the atomic mass.

Atomic weight for elements 93-118: For naturally occurring elements, the atomic weight is calculated from averaging the weights of the natural abundances of the isotopes of that element. However, for man-made trans-uranium elements there is no “natural” abundance. The convention is to list the atomic weight of the longest-lived isotope in the periodic table. These atomic weights should be considered provisional since a new isotope with a longer half-life could be produced in the future.

Within this man-made category are the superheavy elements, or those with atomic numbers above 104. The larger the atom’s nucleus — which increases with the number of protons inside — the more unstable that element is, generally. As such, these outsized elements are fleeting, lasting mere milliseconds before decaying into lighter elements, according to the International Union of Pure and Applied Chemistry (IUPAC). For instance,superheavy elements 113, 115, 117 and 118 were just verified by the IPUACin December 2015, completing the seventh row, or period, on the table. Several different labs produced the superheavy elements.

“The chemistry community is eager to see its most cherished table finally being completed down to the seventh row. IUPAC has now initiated the process of formalizing names and symbols for these elements,” Jan Reedijk, president of the Inorganic Chemistry Division of IUPAC, said in an IUPAC statement.

Element No. Sym Element No. Sym Element No. Sym
Actinium 89 Ac Hafnium 72 Hf Protactinium 91 Pa
Aluminum 13 Al Hassium 108 Hs Radium 88 Ra
Americium 95 Am Helium 2 He Radon 86 Rn
Antimony 51 Sb Holmium 67 Ho Rhenium 75 Re
Argon 18 Ar Hydrogen 1 H Rhodium 45 Rh
Arsenic 33 As Indium 49 In Roentgenium 111 Rg
Astatine 85 At Iodine 53 I Rubidium 37 Rb
Barium 56 Ba Iridium 77 Ir Ruthenium 44 Ru
Berkelium 97 Bk Iron 26 Fe Rutherfordium 104 Rf
Beryllium 4 Be Krypton 36 Kr Samarium 62 Sm
Bismuth 83 Bi Lanthanum 57 La Scandium 21 Sc
Bohrium 107 Bh Lawrencium 103 Lr Seaborgium 106 Sg
Boron 5 B Lead 82 Pb Selenium 34 Se
Bromine 35 Br Lithium 3 Li Silicon 14 Si
Cadmium 48 Cd Livermorium 116 Lv Silver 47 Ag
Calcium 20 Ca Lutetium 71 Lu Sodium 11 Na
Californium 98 Cf Magnesium 12 Mg Strontium 38 Sr
Carbon 6 C Manganese 25 Mn Sulfur 16 S
Cerium 58 Ce Meitnerium 109 Mt Tantalum 73 Ta
Cesium 55 Cs Mendelevium 101 Md Technetium 43 Tc
Chlorine 17 Cl Mercury 80 Hg Tellurium 52 Te
Chromium 24 Cr Molybdenum 42 Mo Terbium 65 Tb
Cobalt 27 Co Neodymium 60 Nd Thallium 81 Tl
Copernicium 112 Cn Neon 10 Ne Thorium 90 Th
Copper 29 Cu Neptunium 93 Np Thulium 69 Tm
Curium 96 Cm Nickel 28 Ni Tin 50 Sn
Darmstadtium 110 Ds Niobium 41 Nb Titanium 22 Ti
Dubnium 105 Db Nitrogen 7 N Tungsten 74 W
Dysprosium 66 Dy Nobelium 102 No Ununoctium 118 Uuo
Einsteinium 99 Es Osmium 76 Os Ununpentium 115 Uup
Erbium 68 Er Oxygen 8 O Ununseptium 117 Uus
Europium 63 Eu Palladium 46 Pd Ununtrium 113 Uut
Fermium 100 Fm Phosphorus 15 P Uranium 92 U
Flerovium 114 Fl Platinum 78 Pt Vanadium 23 V
Fluorine 9 F Plutonium 94 Pu Xenon 54 Xe
Francium 87 Fr Polonium 84 Po Ytterbium 70 Yb
Gadolinium 64 Gd Potassium 19 K Yttrium 39 Y
Gallium 31 Ga Praseodymium 59 Pr Zinc 30 Zn
Germanium 32 Ge Promethium 61 Pm Zirconium 40 Zr
Gold 79 Au
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Facts About Vanadium


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Facts About Vanadium

Vanadinite is a mineral that is an important source of the element vanadium.

Credit: Anneka | Shutterstock

Vanadium is a medium-hard, steel-blue metal. Although a lesser-known metal, it is quite valuable in the manufacturing industry due to its malleable, ductile and corrosion-resistant qualities.

Vanadium rarely exists as a free element in nature but can be found in about 65 different minerals, including magnetite, vanadinite, carnotite and patronite. It also can be found in phosphate rock and some crude oils. Vanadium is usually obtained by heating crushed ore in the presence ofcarbon and chlorine to produce vanadium trichloride, which is then heated with magnesium in an argon atmosphere, according to Jefferson Lab. Around 98 percent of mined vanadium ore comes from South Africa, Russia, and China.

Vanadium makes up 150 parts per million (ppm) of the Earth’s core and comprises 0.019 percent of the Earth’s crust, according toPeriodicTable.com. The cosmic quantity of vanadium in the universe is about 0.0001 percent. Vanadium can be detected spectroscopically in the Sun’s rays and occasionally in the light of other stars.

  • Atomic number (number of protons in the nucleus): 23
  • Atomic symbol (on the periodic table of the elements): V
  • Atomic weight (average mass of the atom): 50.9415
  • Density: grams per cubic centimeter
  • Phase at room temperature: Solid
  • Melting point: 3,470 degrees Fahrenheit (1,910 degrees Celsius)
  • Boiling point: 6,165 F (3,407 C)
  • Number of isotopes (atoms of the same element with a different number of neutrons): 2; one stable V-51; one radioactive V-50
  • Most common isotopes: V-51 (99.75 percent natural abundance)

Vanadium was discovered twice, according to the Royal Society of Chemistry. In 1801, Andrés Manuel del Rio, a professor of mineralogy in Mexico City, discovered it in a specimen of vanadite. He sent samples of the element (which he had named erythronium) along with a letter describing his methods to the Institute de France for inspection and confirmation. Tragically, his letter was lost in a shipwreck, according to theJefferson Lab, and the Institute received only his sample, along with a short note telling them how the new element resembled chromium. The Institute concluded that the sample was, in fact, a chromium mineral, and del Rio withdrew his claim.

Later, in 1830, vanadium was rediscovered by Swedish chemist Nils Gabriel Sefstrôm as he was analyzing samples of iron from a mine in Sweden. Possibly inspired by the element’s beautifully-colored compounds, Sefström named the element vanadium after the Old Norse goddess Vanadis, the old Norse name for Freya, who is associated with beauty and fertility.

The element was finally isolated in 1867 by the English chemist Sir Henry Enfield Roscoe when he was combining vanadium trichloride (VCl3) with hydrogen gas (H2).

High doses of vanadium are toxic to humans, but scientists think we may need the element in very small amounts for normal bone growth. Vanadium can be found in trace amounts in many types of food, including mushrooms, black pepper, parsley, dill weed, shellfish, beer, wine and grain. When we eat a balanced diet, we consume just 0.01 milligrams per day, and this is more than enough for our biological needs, according to the Royal Society of Chemistry.

Very few vanadium studies have involved humans (most have been conducted on animals), so vanadium isn’t currently recommended for any particular diseases or health conditions. However, several animal studies and a few small human studies suggest that vanadium may lower blood sugar levels and improve insulin sensitivity in patients with type 2 diabetes, according to the University of Maryland Medical Center.

In some studies on mice, for example, vanadium was shown to lower blood sugar and levels of low-density lipoprotein (LDL) cholesterol andtriglyceride. In a 1994 study on goats, published in the Journal of the American Dietetic Association, goat kids whose mothers consumed a diet deficient in vanadium were born with skeletal deficiencies and died three days later.

Many of the human studies with vanadium involved small numbers of people for short periods of time and with high doses, well above the tolerable upper intake level (UL), and scientists don’t know if these levels are even safe for human consumption.

Vanadium is sold as a bodybuilding supplement typically in the form of vanadyl sulfate. The supplement is marketed as a way to increase muscle uptake of glucose and amino acids and enhance the synthesis of glycogen and protein. However, according to some scientific research, vanadium does not appear to enhance insulin activity in healthy people, only in diabetics, according to Encyclopedia.com.

Around 80 percent of the vanadium produced is alloyed with iron to make a shock- and corrosion-resistant steel additive called ferrovanadium, according to Jefferson Lab. Ferrovanadium contains between 1 to 6 percent vanadium.

Vanadium-steel alloys are used to make extremely tough tools such as axles, armor plates, car gears, springs, cutting tools, piston rods and crankshafts. Vanadium alloys are also used to make nuclear reactors because of their low-neutron-absorbing properties, according to the Royal Society of Chemistry. In fact, the first widespread industrial use for vanadium was in the steel framework of the Model T Ford, which allowed for a lighter weight frame that was also of greater tensile strength.

The compound vanadium pentoxide (V2O5) is used as a mordant (a substance that permanently fixes dyes to fabrics), as a catalyst in some chemical reactions and in the manufacturing of ceramics. It can also be combined with gallium to form superconductive magnets, according to Jefferson Lab. When mixed with aluminum and titanium, vanadium can create a very strong alloy that is used for special applications such as dental implants and jet engines.

  • Inhaling large amounts of vanadium can result in lung problems, such as bronchitis or pneumonia. It has been shown that workers exposed to vanadium peroxide are more susceptible to eye, nose and throat irritation.
  • Vanadium was used to make portable artillery pieces and body armor in World War I.
  • In a 1996 study published in the medical journal Metabolism, eight people with type 2 diabetes were given vanadium supplements for one month. It appeared moderately successful in lowering blood sugar levels with few side effects. During the first week, six of the eight participants experienced some gastrointestinal problems, but these side effects disappeared with continued use.
  • Vanadium has very colorful oxidation states, including purple, green, blue and yellow.
  • In 1911, German chemist Martin Henze discovered vanadium in the blood cells of sea squirts.
  • Vanadium atoms have 23 electrons, 28 neutrons and 23 protons.
  • Since vanadium steel keeps its hardness at high temperatures, it is used in circular saws, drill bits, engine turbines and other moving parts that produce high levels of heat.
  • Vanadium can be used in the process of refining uranium for nuclear purposes.
  • Vanadium is present in a small number of meteorites.

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Blossoming Bisexual: World’s 1st Flower Had Male and Female Parts


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Blossoming Bisexual: World’s 1st Flower Had Male and Female Parts

A 3D model of the reconstructed ancestral flower. It has both female (carpels) and male (stamens) parts, and multiple whorls of petal-like organs in sets of three.

Credit: Hervé Sauquet and Jürg Schönenberger

When the world’s first flower sprouted about 140 million years ago, it was bisexual, possessing both male and female reproductive parts, according to the researchers who virtually reconstructed the blossom in a new study.

The discovery of the dinosaur-age posy sheds light on the evolution anddiversification of flowering plants, or angiosperms, the largest group of plants on Earth, the researchers said. For instance, the reconstruction shows how the ancient flower differed from its numerous modern descendants.

“The petal-like parts and the stamens [male reproductive organs in a flower] were more numerous than in most living species, and were probably organized in multiple sets of three,” said the study’s lead researcher, Hervé Sauquet, an associate professor at the Laboratory of Ecology, Systematics and Evolution at the University of Paris-Sud in France. [Photos: Ancient Flowering Plant May Have Lived with Dinosaurs]

There are many mysteries in plant evolution, and Sauquet and his colleagues were determined to solve one of the biggest ones: what the original angiosperm looked like.

“We know a lot about the evolutionary history of this group, in particular how plant families are related to one another, but we still know very little about how their emblematic structure — the flower — has evolved and diversified since their origin,” Sauquet told Live Science in an email. “That’s why I decided to join forces with other experts and create the international eFLOWER initiative to tackle these questions.”

Because there are no known fossils of the world’s oldest angiosperm— the oldest uncontroversial fossil flower dates to about 130 million years ago, a good 10 million years before the likely birth of the earliest flower — Sauquet and his colleagues used a method known as ancestral state reconstruction, he said.

This simplified map shows that every living flower evolved from this single ancestor (see middle) that lived approximately 140 million years ago.
This simplified map shows that every living flower evolved from this single ancestor (see middle) that lived approximately 140 million years ago.

Credit: Hervé Sauquet and Jürg Schönenberger

This method uses information from the known evolutionary tree — a diagram showing relationships between flowers based on their similarities and differences — and from the known features of living flowers “to make a guess about the structure of ancestral flowers at different points of divergence in the tree,” Sauquet said.

To reveal the first flower’s anatomy, the researchers used probabilistic models that would calculate the likelihood of the emergence of certain floral characteristics throughout time. This method allowed them “not only to find out what ancestral flowers were like, but also to measure uncertainty” around the results, Sauquet said.

The results showed that when flowers first popped up on Earth, they went through a series of simplifications in which structures were reduced or merged until the flowers settled on an optimal and stable architecture, he said.

Once flowers achieved this stable architecture, they likely started to diversify and develop other features, such as symmetry, he noted.

However, there is still much to learn about early angiosperms and their environments. For instance, it’s unclear which animals might have eaten orpollinated these flowers, although “some authors have speculated that flies might have been among the earliest pollinators of flowers,” Sauquet said.

Moreover, studies on fossilized animal poop, known as coprolites, show that certain paleo-beasts munched on angiosperms. For example, an unknown dinosaur — but apparently a large one, judging from the size of its droppings — ate angiosperms about 75 million years ago, according to research presented at the 2015 Society of Vertebrate Paleontology conference in Dallas.

The new study was published online today (Aug. 1) in the journal Nature Communications.

Original article on Live Science.

A History of Global Warming, In Just 35 Seconds


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A History of Global Warming, In Just 35 Seconds

This visualization shows the rhythm of global warming for countries around the world.

Credit: climatecentraldotorg/YouTube

Last year, there was the temperature spiral. This year, it’s the temperature circle that’s making the trend of global warming crystal clear.

A new video shows the rhythm of global warming for countries around the world, from Afghanistan to Zimbabwe. Bars representing each country’s annual average temperature anomaly pulse up and down. It’s like watching a heartbeat on a monitor.

Rather than staying steady like a normal heartbeat, it’s clear that temperatures for more than 100 countries are climbing ever higher on the back of increasing carbon pollution. While there are individual variations in how hot any year is, the signal of climate change is unmistakable.

“There are no single countries that clearly stand out from the graph,” saidAntti Lipponen, a physicist at the Finnish Meteorological Institute who made the graphic. “The warming really is global, not local.”

While the temperature spiral showed the global average temperature, Lipponen’s animation uses NASA data to show individual countries separated by regions. The format invites you to look for your country or the place you took your vacation last year.

But step back to look at the graphic as a whole and it’s clear we’re all in this together. No country is immune from rising temperatures, let alone the other impacts of climate change.

It’s also clear that global warming is accelerating. In the past three decades (which starts around the 14-second mark in the video), the bars start pushing further and further from the center. Cooler-than-normal years start to become more rare and by the 1990s, they’ve almost disappeared completely.

The past three years have been the hottest ones ever recorded. A number of countries were more than 2 degrees Celsius warmer than the 1951-1980 baseline used in the graphic. That puts them well above the warming limitenshrined in the Paris Agreement, serving as a warning of how fast we’re pushing into new territory.

The world itself touched 1.5 degrees Celsius above pre-industrial levels for a few months in 2016. If global warming permanently crosses that threshold, it will likely cause small island states to be swallowed by the sea, coral to die and heat waves to become more common and severe.

Those numbers alone are abstract, though. Even plotted on a line graph, they fail to fully convey the trajectory we’re on.

Lipponen said he made the animation because he wanted a “nice looking, clear, and informative” way to convey that information in a way people can understand. Mission accomplished.

What’s Causing So Many Earthquakes in Oklahoma?


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What’s Causing So Many Earthquakes in Oklahoma?

On Aug. 2, 2017, a 4.2-magnitude earthquake struck north central Oklahoma, a region that has seen an uptick in temblors since 2014.

Credit: USGS

A magnitude-4.2 earthquake hit just outside Edmond, Oklahoma, last night (Aug. 2) at 9:56 p.m. local time — the fifth significant temblor to shake this region of the state already this month, according to the U.S. Geological Survey.

The temblor originated at a depth of 1.9 miles (3 km), about 15 miles (24 km) northeast of Oklahoma City, the USGS said. According to the Edmond police department’s Twitter account, as of last night, no significant damage had been reported. News 9 in Oklahoma City reported that although 4,600 people were left without power after the quake, all power has since been restored. [The 10 Biggest Earthquakes in History]

But last night’s quake is part of a recent trend. Since Tuesday (Aug. 1), five earthquakes above magnitude 3.0 have been reported in this region, Xiaowei Chen, assistant professor of geophysics at the University of Oklahoma, told Live Science. It appears to be part of a longer sequence of earthquakes that began in 2014, she added. In fact, in 2014, the USGS issued an earthquake warning in the central part of the state — the first time the agency had ever issued such a warning for a state east of the Rockies.

Chen didn’t yet know enough about the most recent earthquake sequence to be able to comment on whether this recent magnitude-4.2 earthquake may signal that an even bigger earthquake will come, or if it’s simply within the range of expected seismic activity in the area, she said.

Although it’s difficult to attribute earthquakes to a particular cause, it’s possible that human activity induced this earthquake, William Yeck, a research geophysicist with the USGS Geologic Hazards Science Center, told Live Science. Since 2014, there has been a significant increase in the rate of earthquakes in north central Oklahoma, the area in which this recent earthquake occurred, he said.  The cause of this increase? Theinjection of wastewater — a byproduct of oil and gas production — into the ground may be to blame.

“The injection of fluids underground can increase underground pressures,” he said. “This, in turn, can effectively unclamp faults, allowing them to slip, which results in earthquakes.”

Last year, scientists reported that north central Oklahoma and the southernmost part of Kansas were at the greatest risk of a human-induced earthquake in the United States.

The high rate of earthquakes that began in 2014 began to drop off last year, which Yeck thinks may be due to the decrease in wastewater injection in this area.

“I just stress that [for] people [living] in an area that’s prone to earthquakes, preparedness is key,” he added.

Original article on Live Science.