Period 4 element - wikipedia Period 4 element Period 4 in the periodic table Part of a series on the Periodic table Periodic table forms 18 - column large cells 32 - column ( large cells ) Alternative forms Chemical Galaxy Janet 's left step Beyond period 7 Fricke large cells Pyykkö Periodic table history Dmitri Mendeleev predictions Discovery of elements Naming & etymology for places for scientists controversies ( in East Asia ) Systematic element names Sets of elements By periodic table structure Groups ( 1 -- 18 ) 1 ( alkali metals ) 2 ( alkaline earth metals ) 5 6 7 8 9 10 11 12 13 14 15 ( pnictogens ) 16 ( chalcogens ) 17 ( halogens ) 18 ( noble gases ) Periods ( 1 -- 7... ) 5 6 7 8 + Aufbau Fricke Pyykkö Blocks ( s, p, d, f,... ) Atomic orbitals Aufbau principle By metallic classification Metals alkali alkaline earth transition post-transition lanthanide actinide ( super - / eka - super - ) Metalloids dividing metals & nonmetals Nonmetals polyatomic diatomic monatomic ( noble gas ) By other characteristics Coinage metals Platinum - group metals Precious metals Refractory metals Heavy metals Light metals Native metals Noble metals Main - group elements Rare - earth elements Transuranium, transplutonium elements Major, minor & trans - actinides Elements List of chemical elements... by abundance ( in human body ) by atomic properties by isotope stability by annual production by symbol Properties of elements Atomic weight Crystal structure Electron affinity configuration Electronegativity ( ( Allen ) ) ( ( Pauling ) ) Goldschmidt classification Nutrition Valence Data pages for elements Abundance Atomic radius Boiling point Critical point Density Elasticity Electrical resistivity Electron affinity / configuration Electronegativity Hardness Heat capacity / of fusion / of vaporization Ionization energy Melting point Oxidation state Speed of sound Thermal conductivity / expansion coefficient Vapor pressure Book Category Chemistry Portal A period 4 element is one of the chemical elements in the fourth row ( or period ) of the periodic table of the elements. The periodic table is laid out in rows to illustrate recurring ( periodic ) trends in the chemical behaviour of the elements as their atomic number increases : a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns. The fourth period contains 18 elements, beginning with potassium and ending with krypton. As a rule, period 4 elements fill their 4s shells first, then their 3d and 4p shells, in that order ; however, there are exceptions, such as chromium. Contents 1 Properties 2 Periodic trends 3 List of elements 4 s - block elements 4.1 Potassium 4.2 Calcium 5 d - block elements 5.1 Scandium 5.2 Titanium 5.3 Vanadium 5.4 Chromium 5.5 Manganese 5.6 Iron 5.7 Cobalt 5.8 Nickel 5.9 Copper 5.10 Zinc 6 p - block elements 6.1 Gallium 6.2 Germanium 6.3 Arsenic 6.4 Selenium 6.5 Bromine 6.6 Krypton 7 Biological role 8 References Properties Every single one of these elements is stable, and many are extremely common in the earth 's crust and / or core ; it is the last period with no unstable elements at all. Many of the transition metals in period 4 are incredibly strong, and therefore commonly used in industry, especially iron. Copper is one of three metals that are not silver or gray in color, along with caesium and gold. Three adjacent elements are known to be toxic, with arsenic one of the most well - known poisons, selenium being toxic to humans in large quantities, and bromine, a very toxic liquid. Many elements are essential to humans ' survival, such as calcium being what forms bones. Periodic trends This section needs expansion. You can help by adding to it. ( March 2012 ) Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton List of elements Chemical element Chemical series Electron configuration 19 Potassium Alkali metal ( Ar ) 4s 20 Ca Calcium Alkaline earth metal ( Ar ) 4s 21 Sc Scandium Transition metal ( Ar ) 3d 4s 22 Ti Titanium Transition metal ( Ar ) 3d 4s 23 V Vanadium Transition metal ( Ar ) 3d 4s 24 Cr Chromium Transition metal ( Ar ) 3d 4s ( * ) 25 Mn Manganese Transition metal ( Ar ) 3d 4s 26 Fe Iron Transition metal ( Ar ) 3d 4s 27 Co Cobalt Transition metal ( Ar ) 3d 4s 28 Ni Nickel Transition metal ( Ar ) 3d 4s 29 Cu Copper Transition metal ( Ar ) 3d 4s ( * ) 30 Zn Zinc Post-transition metal ( Ar ) 3d 4s 31 Ga Gallium Post-transition metal ( Ar ) 3d 4s 4p 32 Ge Germanium Metalloid ( Ar ) 3d 4s 4p 33 As Arsenic Metalloid ( Ar ) 3d 4s 4p 34 Se Selenium Polyatomic nonmetal ( Ar ) 3d 4s 4p 35 Br Bromine Diatomic nonmetal ( Ar ) 3d 4s 4p 36 Kr Krypton Noble gas ( Ar ) 3d 4s 4p ( * ) Exception to the Madelung rule Legend for the background color Background color shows subcategory in the metal -- metalloid -- nonmetal trend : Metal Metalloid Nonmetal Unknown chemical properties Alkali metal Alkaline earth metal Lanthanide Actinide Transition metal Post - ​ transition metal Polyatomic nonmetal Diatomic nonmetal Noble gas S - block elements Potassium Potassium ( K ) is an alkali metal, placed under sodium and over rubidium, and is the first element of period 4. It is one of the most reactive elements in the periodic table, therefore usually only found in compounds. It tends to oxidize in air very rapidly, thus accounting for its rapid reaction with oxygen when freshly exposed to air. When freshly exposed, it is rather silvery, but it quickly begins to tarnish as it reacts with air. It is soft enough to be cut with a knife and it is the second least dense element. Potassium has a relatively low melting point ; it will melt just by putting it under a small open flame. It also is less dense than water, and can, in turn, float. Calcium Calcium ( Ca ) is the second element in period 4, between potassium and scandium. An alkali earth metal, calcium is almost never found in nature due to its high reactivity with water. It has one of the most widely known and acknowledged biological roles in all animals and some plants, making up bones and teeth, and used in some applications in cells, such as signals for cellular processeses. It is regarded as the most abundant mineral in the body 's mass. D - block elements Scandium Scandium ( Sc ) is the third element in period 4, between calcium and titanium, and is the first transition metal in the periodic table. Scandium is quite common in nature, but difficult to find because it is most prevalent in rare earth compounds, which are difficult to isolate elements from. Scandium has very few commercial applications because of the aforementioned facts, and currently its only major application is in aluminium alloys. Titanium Titanium ( Ti ) is an element in period 4, between scandium and vanadium. Titanium is both one of the least dense metals and one of the strongest and most corrosion - resistant, and as such has many applications, especially in alloys with other elements, such as iron. Due to its aforementioned properties, it is commonly used in airplanes, golf clubs, and other objects that must be strong, but lightweight. Vanadium Vanadium ( V ) is an element in period 4, between titanium and chromium. Vanadium is never found in pure form in nature, but is commonly found in compounds. Vanadium is similar to titanium in many ways, such as being very corrosion - resistant, however, unlike titanium, it oxidizes in air even at room temperature. All vanadium compounds have at least some level of toxicity, with some of them being extremely toxic. Chromium Chromium ( Cr ) is an element in period 4, between vanadium and manganese. Chromium is, like titanium and vanadium before it, extremely resistant to corrosion, and is indeed one of the main components of stainless steel. Chromium also has many colorful compounds, and as such is very commonly used in pigments, such as chrome green. Manganese Manganese ( Mn ) is an element in period 4, between chromium and iron. Manganese is often found free in nature, but is also found in combination with iron. Manganese, like chromium before it, is an important component in stainless steel, preventing the iron from rusting. Manganese is also often used in pigments, again like chromium. Manganese is also poisonous ; if enough is inhaled, it can cause irreversible neurological damage. Iron Iron ( Fe ) is an element in period 4, between manganese and cobalt. Iron is probably the most well - known element in period 4, being the most common element in the earth and a major component of steel. Iron - 56 has the lowest energy density of any isotope of any element, meaning that it is the most massive element that can be produced in supergiant stars. Iron also has some applications in the human body ; hemoglobin is partly iron. Cobalt Cobalt ( Co ) is an element in period 4, between iron and nickel. Cobalt is commonly used in pigments, as many compounds of cobalt are blue in color. Cobalt is also a core component of many magnetic and high - strength alloys. The only stable isotope, cobalt - 59, is an important component of vitamin B - 12, while cobalt - 60 is a component of nuclear fallout and can be dangerous in large enough quantities due to its radioactivity. Nickel Nickel ( Ni ) is an element in period 4, between cobalt and copper. Nickel is rare in the earth 's crust, mainly due to the fact that it reacts with oxygen in the air, with most of the nickel on earth coming from nickel iron meteorites. However, nickel is incredibly common in the earths core ; along with iron it is one of the two main components. Nickel is an important component of stainless steel, and in many superalloys. Copper Copper ( Cu ) is an element in period 4, between nickel and zinc. Copper is one of the few metals that is not white or gray in color, the only others being gold and caesium. Copper has been used by humans for thousands of years to provide a reddish tint to many objects, and is even an essential nutrient to humans, although too much is poisonous. Copper is also commonly used as a wood preservative or fungicides. Zinc Zinc ( Zn ) is an element in period 4, between copper and gallium. Zinc is one of the main components of brass, being used since the 10th century BCE. Zinc is also incredibly important to humans ; almost 2 billion people in the world suffer from zinc deficiency. However, too much zinc can cause copper deficiency. Zinc is often used in batteries, aptly named carbon - zinc batteries, and is important in many platings, as zinc is very corrosion resistant. P - block elements Gallium Gallium ( Ga ) is an element in period 4, between zinc and germanium. Gallium is noteworthy because it has a melting point at about 303 kelvins, right around room temperature. For example, it will be solid on a typical spring day, but will be liquid on a hot summer day. Gallium is an important component in the alloy galinstan, along with tin. Gallium can also be found in semiconductors. Germanium Germanium ( Ge ) is an element in period 4, between gallium and arsenic. Germanium, like silicon above it, is an important semiconductor and is commonly used in diodes and transistors, often in combination with arsenic. Germanium is fairly rare on earth, leading to its comparatively late discovery. Germanium, in compounds, can sometimes irritate the eyes, skin, or lungs. Arsenic Arsenic ( As ) is an element in period 4, between germanium and selenium. Arsenic, as mentioned above, is often used in semiconductors in alloys with germanium. Arsenic, in pure form and some alloys, is incredibly poisonous to all multicellular life, and as such is a common component in pesticides. Arsenic was also used in some pigments before its toxicity was discovered. Selenium Selenium ( Se ) is an element in period 4, between arsenic and bromine. Selenium is the first nonmetal in period 4, with properties similar to sulfur. Selenium is quite rare in pure form in nature, mostly being found in minerals such as pyrite, and even then it is quite rare. Selenium is necessary for humans in trace amounts, but is toxic in larger quantities. Bromine Bromine ( Br ) is an element in period 4, between selenium and krypton. Bromine is a halogen, never existing in pure form in nature. Bromine is barely liquid at room temperature, boiling at about 330 kelvins. Bromine is also quite toxic and corrosive, but bromide ions, which are relatively inert, can be found in halite, or table salt. Bromine is often used as a fire retardant because many compounds can be made to release free bromine atoms. Krypton Krypton ( Kr ) is a noble gas, placed under argon and over xenon. Being a noble gas, krypton rarely interacts with itself or other elements ; although compounds have been detected, they are all unstable and decay rapidly, and as such, krypton is often used in fluorescent lights. Krypton, like most noble gases, is also used in lighting because of its many spectral lines and the aforementioned reasons. Biological role This section needs expansion. You can help by adding to it. ( February 2012 ) References Jump up ^ `` List of Elements of the Periodic Table -- Sorted by Abundance in Earth 's crust ''. Science.co.il. Retrieved 2012 - 08 - 14. Jump up ^ Gray, Theodore ( 2009 ). The Elements : A Visual Exploration of Every Known Atom in the Universe. New York : Black Dog & Leventhal Publishers. ISBN 978 - 1 - 57912 - 814 - 2. Jump up ^ `` Elements in the Modern Periodic Table, Periodic Classification of Elements ''. Tutorvista.com. Retrieved 2012 - 08 - 14. Jump up ^ `` It 's Elemental -- The Element Potassium ''. Education.jlab.org. Retrieved 2012 - 08 - 14. Jump up ^ `` Potassium, Chemical Element -- Overview, Discovery and naming, Physical properties, Chemical properties, Occurrence in nature, Isotopes ''. Chemistryexplained.com. Retrieved 2012 - 08 - 14. Jump up ^ `` Potassium ( K ) -- Chemical properties, Health and Environmental effects ''. Lenntech.com. Retrieved 2012 - 08 - 14. Jump up ^ `` Reactions of the Group 2 elements with water ''. Chemguide.co.uk. Retrieved 2012 - 08 - 14. Jump up ^ `` Chapter 11. Calcium ''. Fao.org. Retrieved 2012 - 08 - 14. Periodic table Periodic table forms Standard 18 - column 18 - column, large cells 32 - column, large cells Alternative Alternatives Chemical Galaxy Janet 's left step table Extended Extension beyond the 7th period Fricke model large cells Pyykkö model Sets of elements By periodic table structure Groups 1 ( Alkali metals ) 2 ( Alkaline earth metals ) 5 6 7 8 9 10 11 12 13 14 15 ( Pnictogens ) 16 ( Chalcogens ) 17 ( Halogens ) 18 ( Noble gases ) Periods 5 6 7 8 + Aufbau Fricke Pyykkö Blocks s - block p - block d - block f - block g - block Aufbau principle By metallicity Metals Alkali metals Alkaline earth metals Lanthanides Actinides Superactinides Eka - superactinides Transition metals Post-transition metals Metalloids Lists of metalloids by source Dividing line Nonmetals Polyatomic nonmetals Diatomic nonmetals Noble gases Other sets Nutritional elements Platinum - group metals ( PGM ) Rare - earth elements Refractory metals Precious metals Coinage metals Noble metal Heavy metals Native metals Transuranium elements Transactinide elements Major actinides Minor actinides Elements Lists By : Abundance ( in humans ) Atomic properties Nuclear stability Production Symbol Properties Atomic weight Crystal structure Electron affinity Electron configuration Electronegativity Allen Pauling Goldschmidt classification Maximum valence Data pages Abundance Atomic radius Boiling point Critical point Density Elasticity Electrical resistivity Electron affinity Electron configuration Electronegativity Hardness Heat capacity Heat of fusion Heat of vaporization Ionization energy Melting point Oxidation state Speed of sound Thermal conductivity Thermal expansion coefficient Vapor pressure History Element discoveries Mendeleev 's predictions Naming Etymology controversies places scientists in East Asia See also IUPAC nomenclature systematic element name Trivial name Dmitri Mendeleev Book Category Chemistry Portal Periodic table ( Large cells ) 5 6 7 8 9 10 11 12 13 14 15 16 17 18 He Li Be Ne Na Mg Al Si Cl Ar Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te Xe 6 Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 7 Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og Alkali metal Alkaline earth metal Lanthanide Actinide Transition metal Post - ​ transition metal Metalloid Polyatomic nonmetal Diatomic nonmetal Noble gas Unknown chemical properties Retrieved from `` https://en.wikipedia.org/w/index.php?title=Period_4_element&oldid=800863497 '' Categories : Periods in the periodic table Hidden categories : Articles to be expanded from March 2012 All articles to be expanded Articles using small message boxes Articles to be expanded from February 2012 Pages containing element color directly Talk Contents About Wikipedia Aragonés Asturianu Azərbaycanca বাংলা भोजपुरी Català Cymraeg Dansk Deutsch Español Esperanto Euskara فارسی Français 한국어 Bahasa Indonesia Interlingua Italiano Latina Lumbaart Македонски Bahasa Melayu Nederlands 日本 語 Nordfriisk ਪੰਜਾਬੀ Polski Русский Simple English Slovenčina Српски / srpski Srpskohrvatski / српскохрватски Suomi தமிழ் ไทย Türkçe Tiếng Việt 中文 Edit links This page was last edited on 16 September 2017, at 04 : 02. 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Question: what is the name of the 4th halogen
Answer: Bromine