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Alkali Metals

Added Feb 20, 2018 •

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the alkali metals are soft metals that tarnish rapidly even in dry air they have lower melting points and lower densities than most other metals I will react violently with water and as a result are never found uncombined in nature lithium is the least dense of all the metals it is sometimes used to make lightweight steel Alloys for high performance aircraft sodium is the sixth most abundant element on Earth it's many uses range from table saw two batteries and it is one of the main components in seawater that makes it undrinkable potassium is the seventh most abundant element on Earth it goes into glass soap and explosives rubidium is used in photoelectric cells vacuum tubes and heart research cesium a Rare Element particularly reacts with other elements scientists use it to help calibrate atomic clocks and francium is possibly the rarest element on Earth it is very short lived in a cruise is a Radioactive by product of uranium decay there was less than 1 oz of francium in the Earth's crust at any one time like most other metals the alkaline metals are silly metallic solids they are excellent conductors of electricity and heat the alkali metals are very reactive and they easily form compounds with other elements these compounds are generally out which are capable of neutralizing acids because they are so reactive the alkali metals are never found uncombined in nature in their pure forms the alkali metals must be stored under oil or kerosene keep them from interacting with oxygen or water vapor in the air the alkali metals are as soft as cold butter and much less dense than most other metals lithium sodium and potassium are evenly dense than water so they will actually float coming into contact with water alkaline metals interact to form oxides or hydroxides hydrogen gas and heat when lithium is placed in cold water it melts plate and moves around the surface of the water fizzing and this reaction becomes increasingly violent as you go down the group of alkali metals cesium is so reactive that it explodes when exposed to water looking at the periodic table can help explain the reactivity of the alkali metals on the periodic table the elements are listed in order of their atomic number the atomic number represents the number of pro Don's in an element's nucleus and it's normal or gram State this nucleus is also surrounded by an equal number of electrons and as the atomic number increases generally so does the size and Mass the Adams as you read the table from top to bottom each horizontal line is called a. Each. Represents the number of electron shells the elements atoms normally have sample there are four electron shells in an atom of potassium so it lies in. For meanwhile and atom of cesium in. 6 has 6 electrons shells as you read the table from left to right the vertical lines of L which are called groups elements in a group have the same number of electrons in their outermost electron shells these outermost electrons are called valence electrons and they dictate how elements interact elements in the same generally interact with other elements in similar ways none of the elements greater than atomic number 83 are completely stable all of these elements including francium are radioactive all alkali metals reside in group one because they each have only one electron in their outermost electron shell because atoms need eight electrons in their valence shell to be stable the single valence electron in the alkali metals makes them very unstable and they easily lose this electron to other elements generally As you move down through a group the atoms hold on their valence electrons becomes weaker so as you move from lithium to francium each element is more reactive than the one before it element number 3 on the periodic table is Lithia the atomic symbol for lithium is Li lithium a soft silvery white metal is the lightest of all the metals its density is only about half that of water lithium gets its name from the Greek Ford leases which means Stone because it was first discovered in mineral deposits lithium is classified as an Alkali metal and lies and the periodic table second row called. 2 each atom of what consists of a cloud of electrons surrounding a compact nucleus that contains almost all the atom's mass in the most common form of lithium its nucleus has three positively charged protons plus for uncharged new there are three negatively charged electrons to balance its three protons these electrons are found in two shells that surround the nucleus which can be visualized as being built up from the nearest preceding noble gas helium helium has two electrons distributed in a single electron shell lithium's additional electron is found in a spherical 2's orbital shell like the other alkali metals which also only one valence electron lithium react easily with other elements by losing the electron in this experiment 1 gram of lithium metal is held inside a glass vial when the vial is smashed Sam falls into a bowl of water it reacts vigorously with the water to produce milky white lithium hydroxide and hydrogen gas which can be seen here as bubbles does lithium is only about half as dense as the metal pieces actually float on the surface and are pushed around by the escaping hydrogen until they are consumed well lithium is highly reactive it is the least reactive of all the alkali metals so the Heat and steam that produces is now not to ignite the escaping hydrogen industrially lithium is used in lubricants are combined with other metals to increase the strength of metal alloys it is used to make batteries such as the ones inside mini cellular phones also is probably prepared by medical professionals lithium salt can act as a stimulant in the human brain and is often used to help relieve depression today's high performance jet airplanes have come a long way since the first airplane flew more than a hundred years ago when the Wright brothers first took to the skies in 1903 firewood made mainly of spruce and bamboo what aircraft were successful during the early days of flight but the strength of wood limited their size the weight they could carry and how fast they could go soon aircraft designers turn to build an aircraft out of metal Metals improved airplane stability increase their strength to weight ratio and greatly improve their performance aluminum is a widely used metal in the air what industry because it is light and it resists corrosion well but aluminum is too weak and bendable to be used by itself in many airplane parts so other metals are added to aluminum to make alloys that are harder and stronger than aluminum on its own the chemical properties of lithium make it an excellent metal to add to aluminum since lithium is the lightest metallic element its Alloys are also very light but they are also very strong resistant to fatigue this combination of toughness and lightness make aluminum lithium Alloys a good match for aircraft aluminum lithium Alloys are expensive to create so commercial aircraft use them mainly parts that need to be exceptionally strong and light such as Wing edges and seat tracks aluminum lithium Alloys are used more often in the bodies and armor of high-performance military aircraft where it's high strength-to-weight ratio Jets helicopters and other vehicles deal with the extreme stress as they are put under aluminum lithium Alloys are also used to even higher up in space space vehicles in Satellite Systems need lightweight Plies because every kilogram of weight saves can be vital to a mission success aluminum lithium Alloys also react well to cold so they can be used in the fuel tanks that helped Propel Rockets and the space shuttle into orbit so thanks to the unique chemical properties of lithium this guy is most certainly not the limit element number 11 on the periodic table is soda the atomic symbol for sodium is na sodium is a soft silvery white metal that oxidizes quickly in the air and reacts explosively with water sodium's unusual atomic symbol na comes from the word natrium the Latin name for one of the compound sodium is found in sodium is classified as an Alkali metal and it lies on the third row of the periodic table called. 3 each atom of sodium consists of a cloud of electrons surrounding a compact nucleus that contains almost all the atom's mass in the most common form of sodium its nucleus as 11 positively charged protons and 12 uncharged neutrons sodium has 11 negatively charged electrons to balance its 11 protons these electrons are found in three shells around the nucleus which can be visualized as being built up from the nearest preceding noble gas Neon neon has 10 electrons distributed into electron shells single additional electron and sodium is found in the spiracle 3s orbital shell sodium like the other alkali metals is highly reactive and losses this lone valence electron readily pure sodium has a silvery-white appearance but tarnishes easily and moist air sodium must be handled with gloves because it is highly reactive with water and can easily cause Burns year 50 g of sodium are loaded onto a device on a platform floating on a leg the device has a pail of water and a hinged arm holding a crucible above it which can be released from a safe distance when is sodium is dropped into the water it will instantly generate a large amount of heat and release a cloud of hydrogen gas the hydrogen gas will rise and mixed with oxygen in the air to form an explosive mixture the heat from the reacting sodium then ignites the hydrogen and the mixture explodes the same experiment was repeated at night using 200 grams of sodium and the got you is even more spectacular the compound sodium chloride is the chemical name for table salt an important part of our diet sodium is used batteries and glass sodium vapor goes into street lights and liquid sodium sometimes cools nuclear reactors sodium is also used in agriculture and Medicine Island life has definite benefits for people who enjoy living near the ocean but one of the drawbacks of living on an island is that residents must be fairly so sufficient if they run out of a Central Supply such as food or water it can be difficult and expensive to import them that's just the problem the people of Santa Catalina face when their Island began to run short on drinkable water Catalina is an island off the coast of Southern California recent booms in population and tourism work great for the local economy but also push the communities water supply to limits there just wasn't enough fresh drinking water to go around two residents turn to the ocean to meet their needs anyone who has ever accidentally swallowed a mouthful of C water knows the drinking too much of it can make you sick it's undrinkable because unlike freshwater seawater contains over 70 different minerals dissolved in it the vast majority of these minerals are chloride and sodium sodium atoms have an extra electron in their outermost shell while chlorine atoms are one short of having a filled outer shell as a result when they come together sodium don't extra electron to chlorine and they combine to form sodium chloride sodium chloride is otherwise known as salt but if you can separate the salt from seawater you are left with pure fresh drinkable water the process of removing salt from seawater is called desalination and it's just what the people of Catalina are doing Pedley Beach was the first commercial desalination plant the plant uses process called reverse osmosis reverse osmosis involves high pressure pumps pushing sea water through a semi-permeable membrane or synthetic filter as water passes through the membrane the salt and other minerals are there Behind these were taking spicy water were pressurizing at the 800 pounds per square inch and we're pushing it through a semi-permeable membrane through this channel here that looks similar to that screen door in the freshwater is squeezed through the semipermeable membrane to a Wiccan side and pulls around and comes out the product and all we're doing is squeezing out the fresh water can we call it fresh squeeze water the semi permeable membranes have microscopic holes that allow the smaller elements such as hydrogen and oxygen to pass through but the larger molecules of sodium and chloride are stopped in their tracks for everything gallons of seawater pumped into the plant about 9 gallons of drinkable water come out the leftover salt and other materials get pumped back into the ocean this desalination plant produces about to 3000 gallons of drinkable water everyday that's about 20% of the islands total drinking water and it's all courtesy of our growing understanding of the unique chemistry of seawater element number 19 on the periodic table is potassium the atomic symbol for potassium is K potassium is a very soft wax a shiny metal with a slight purple Hue that is caused by oxidation potassium gets its name from the English word potash because one of the earliest ways of obtaining the element was to use an iron pot to dry the pictures of burnt potassium bearing plants potassium guess it's unusual atomic symbol K from the Latin word column which means alkali potassium is classified as an alkali metal speed lines on the periodic tables for throw. For which atom of potassium consists of a cloud of electrons surrounding a compact nucleus that contains almost all the atoms math in the most common form of potassium its nucleus has 19 positively charged protons plus 20 uncharged neutrons potassium has 19 negatively charged electrons to balance it's 19 protons these electrons are found in for orbital shell surrounding the nucleus which can be visualized as being built up from the nearest preceding noble gas Argon argon has 18 electrons distributed among three orbital shells the additional electron and potassium is found in the spherical for as orbital shell potassium is very reactive and will typically lose its single valence electron when bonding with other elements in this experiment a small glass vial containing small pieces of potassium is broken over a bowl of water potassium reacts violently with the water and releases hydrogen which ignites almost instantly due to the heat of the reaction the potassium melts and reacts with water to form liquid droplets of alkali potassium hydroxide which quickly dissolves in the water potassium compounds are used in fertilizers salt substitutes I didn't making soap and detergent potassium is also used in pyrotechnics to generate ammo color element number 37 on the periodic table Is Rubidium the atomic symbol for rubidium is RB rubidium is a soft silvery white metal rubidium gets its name from the Latin word rubidus meaning deep red which is the color it sounds produced when burned Ruby what is classified as an Alkali metal in the periodic tables fit Row. 5 each rubidium atom consists of a cloud of electrons surrounding a compact nucleus that contains almost all Adams Mass in the most common form of Rubidium its nucleus has 37 positively charged protons plus 48 uncharged neutrons rubidium has 37 negatively charged electrons the balance it's 37 protons these electrons are found in 5 orbital shell surrounding the nucleus which can be visualized as being built up from the nearest preceding noble gas Krypton Krypton has 36 electrons distributed among for orbital shells rubidium single additional electron is found in the spherical 5S orbital shell this single Bailey electron makes rubidium very reactive and it will typically lose this electron when it interacts with other elements can this experiment a small glass bottle containing rubidium is broken over a bowl water reacting quickly with the water the element produces heat although it can't be seen the rubidium and water combine to form a solution of Rubidium hydroxide and hydrogen gas because it reacts so easily with other elements rubidium is used to remove Trace gases and vacuum tube had to manufacture photoelectric cells in the future rubidium may be used as a propellant if ion engines for space vehicles element number 55 on the periodic table is cesium the atomic symbol for is CS cesium is a pliable silver white metal it is the most alkaline of all the elements and one of only three Metals along with Mercury and gallium that are liquid at room temperature Liam gets its name from the Latin word quesadillas which means sky blue the color cesium produces when viewed through a spectroscope cesium is classified as an Alkali metal and it lies in the periodic tables fix the row period each atom of cesium consists of a cloud of electrons surrounding a compact nucleus that contains almost all the atom's mass in the most common form of cesium its nucleus has to 5 positively charged protons plus 78 uncharged neutrons cesium has 55 negatively charged electrons to balance its 55 protons these electrons are Jordan 6 orbital shell surrounding the nucleus which can be visualized as being built up from the nearest preceding noble gas Xenon Xenon has 54 electrons distributed among five orbital shells Liam has one more electrons in Xenon this single electron is found in the sphere shaped 6s orbital shell cesium like the other Alkali metal is highly reactive and losses this loan valence electron readily to elements in this experiment 1 gram of cesium is contained in a glass vial and attached to a device which can be operated from a safe distance when the vial is smashed it released cesium into a bowl of water cesium reacts very rapidly with water to form a colorless solution of cesium hydroxide and hydrogen gas the reaction creates a large amount of heat and it's so energetic most of the water is hurled out of the bowl by the resulting explosion cesium is extremely reactive it explodes when it comes into contact with cold water and it even reacts to light rays as a result element is often used in infrared lamps Optical instrument and photoelectric cells medium compounds are used to make glass and ceramics and cesium-137 a radioactive waste product of nuclear war actors is sometimes used to kill certain kinds of cancer cells widely used mechanical clocks of the 1500s used coiled spring to keep but these clocks were not very reliable they could gain or lose as much as 15 minutes a day by the mid 1600 the invention of the pendulum clock improved our ability to keep time pendulum clocks could keep time to within 15 seconds a day the early Clocks Were nothing compared to the atomic clocks of today the most common atomic clocks used element cesium to keep time cesium atomic clocks measure the vibrations of the outer electrons within a beam of cesium atoms cesium atom vibrates at Ali at more than 9 million cycles per second a TDM atoms pass through a magnetic field the frequency of their vibrations can be used to calibrate the ticking of a clock the first season clock was put into operation in England in 1955 scientists estimate that it will gain or lose less than a second every 3 million years the new arcesium clock designs are even more accurate AutoZone Eastern Daylight Time 15 hours 54 minutes exactly the US Naval Observatory operates about 70 atomic clocks the average of these atomic clocks creates the master times that go that is broadcast by satellites circling the earth Navy ships depend on this system for navigation the system is called GPS for global positioning system it depends on 24 navstar satellites that Circle the globe in synchronized orbits the satellite sent information to the receivers on Earth Beach signal arrives at a slightly different time depending on the distance of the satellite the GPS receiver computer the time delays and can figure out a satellites location Jeep is finding its way into new places GPS receivers are helping lost hikers find their way synchronizing the distribution of power and assisting mass transit vehicles and avoiding collisions and many equipped with talking navigation systems to so thanks to cesium clocks in GPS more people will be able to get where they need to go and get there on time element number 87 on the periodic table is francium the atomic symbol for francium is fr this sample of uranium contains of very small quantity of the element francium the element francium is named for France the native country of the elements discover Marguerite. Francium is classified is an Alkali metal in the periodic table 7 Pro. 7 each atom of francium consists of a cloud of electrons surrounding a compact nucleus that contains almost all the atom's mass in the most common form of francium its nucleus has 87 positively charged protons plus 136 uncharged neutrons francium has 87 negative they charged electrons to balance it for 87 protons these electrons are found in 7 orbital shell surrounding the nucleus which can be visualized is being built up from the nearest preceding noble gas radar radon has 86 electrons distributed among six orbital shells francium has one more electron then radon this single electron is found in the spiracles 7 S4 Michelle francium like the other Alkali metal is highly reactive and loses this loan valence electron readily to other elements my new traces of francium are present in piece of uranium or they are generally found in Paul uranium minerals part of the radioactivity given off by this for his duty Ducane francium and can be detected with a geiger counter each click represents one Decay event francium is one of the rarest naturally occurring elements and the most unstable of the first 101 elements on the periodic due to the very small amount and extremely short half-life of francium it has no current use outside of basic scientific research its longest-lived isotope francium-223 has a half-life of just 22 minutes francium atoms are constantly being created as a step in the Decay sequence of uranium-235

Uploaded by Debra Hood.

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Alkali Metals

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