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Metals

Metals in Periodic Table of Elements

Metals in chemistry are chemical elements that are good conductors of heat and electricity and form positive ions by losing electrons. According to the properties, 118 chemical elements present in the periodic table can be divided into two main types metal and non-metal. Metal is a substance that is produced naturally on the Earth’s surface. Around 95 of the 118 elements in the periodic table are classified as metals. Iron, aluminum, copper, silver, and gold are familiar examples of metals because they are used widely in our everyday lives.

Metals (name, symbol, atomic number) on the periodic table

Most of these metals are very strong and durable. Therefore, they are used for making various daily items such as automobiles, satellites, cooking utensils, etc.

Types of Metals in Periodic Table

93 out of 118 elements in the modern periodic table are metals, while the remaining 18 are nonmetals and 7 are metalloids. Most nonmetals are gases but most metals are solid at standard temperature and pressure.

All the metals present in the periodic table are classified into the following six categories:

  1. Alkali metals
  2. Alkaline earth metals
  3. Transition metals
  4. Basic metals
  5. Lanthanides (rare earth elements)
  6. Actinides

Alkali Metals in Periodic Table

Alkali metals are members of the s-block elements and thus they are present on the leftmost side of the periodic table. All these metallic elements are shiny, soft, and highly reactive at standard temperature and pressure.

They readily lose their outermost electron to form unipositive cations with a charge of +1. Along with hydrogen, they constitute group 1 of the periodic table.

Atomic Number Name of the Metal Symbol Electronic configuration
3 Lithium Li [He] 2s1
11 Sodium Na [Ne] 3s1
19 Potassium K [Ar] 4s1
37 Rubidium Rb [Kr] 5s1
55 Caesium Cs 6s1
87 Francium Fr [Rn] 7s1

Alkaline Earth Metals in Periodic Table

The alkaline earth metals are six chemical elements (beryllium, magnesium, calcium, strontium, barium, and radium) in group 2 of the periodic table. All elements of group 2 are shiny, silvery-white, and readily loose to form cations with a charge of +2 and an oxidation state of +2. Therefore, they are reactive metals at standard temperature and pressure.

The atomic number, name, symbol, and valence shell electronic configuration of alkaline earth metals are given below the table,

Atomic Number Name of the Metal Symbol Electron Configuration
4 Beryllium Be [He] 2s2
12 Magnesium Mg [Ne] 3s2
20 Calcium Ca [Ar] 4s2
38 Strontium Sr [Kr] 5s2
56 Barium Ba [Xe] 6s2
88 Radium Ra [Rn] 7s2

Transition Metals in Periodic Table

In learning chemistry, a transition metal is an element that contains partly filled d orbitals in its atomic state or any of its common oxidation states.

Therefore, transition metals are placed in the d-block of the periodic table. These metals lie between s- and p-block elements of the periodic table and thus they are collectively called transition metals.

The atomic number, name, and symbol of d-block elements are given below the table,

3d-Block Scan­dium21Sc44.956 Tita­nium22Ti47.867 Vana­dium23V50.942 Chrom­ium24Cr51.996 Manga­nese25Mn54.938 Iron26Fe55.845 Cobalt27Co58.933 Nickel28Ni58.693 Copper29Cu63.546 Zinc30Zn65.38
4d-Block Yttrium39Y88.906 Zirco­nium40Zr91.224 Nio­bium41Nb92.906 Molyb­denum42Mo95.95 Tech­netium43Tc[97] Ruthe­nium44Ru101.07 Rho­dium45Rh102.91 Pallad­ium46Pd106.42 Silver47Ag107.87 Cad­mium48Cd112.41
5d-Block Lan­thanum57La138.91 Haf­nium72Hf178.49 Tanta­lum73Ta180.95 Tung­sten74W183.84 Rhe­nium75Re186.21 Os­mium76Os190.23 Iridium77Ir192.22 Plat­inum78Pt195.08 Gold79Au196.97 Mer­cury80Hg200.59
6d-Block Actin­ium89Ac[227] Ruther­fordium104Rf[267] Dub­nium105Db[268] Sea­borgium106Sg[269] Bohr­ium107Bh[270] Has­sium108Hs[269] Meit­nerium109Mt[278] Darm­stadtium110Ds[281] Roent­genium111Rg[282] Coper­nicium112Cn[285]

Basic Metals

The basic metals are located to the right of the transitional metals on the periodic table. They are also called post-transitional metals.

Such types of metals conduct heat and electricity. Like other metals, they also form a metallic luster and tend to be dense, malleable, and ductile.

The atomic number, name, and symbol of basic or post-transition metals are listed below the table:

Atomic number Symbol Name of the metal Electronic configuration
13 Aluminum Al [Ne]3s23p1
31 Gallium Ga [Ar]3d104s24p1
49 Indium In [Kr]4d105s25p1
50 Tin Sn [Kr]4d105s25p2
81 Thallium Tl [Xe]4f145d106s26p1
82 Lead Pb [Xe]6s24f145d106p2
83 Bismuth Bi [Xe]6s24f145d106p3
113 Nihonium Nh [Rn]5f146d107s27p1 (predicted)
114 Flerovium Fl [Rn]5f146d107s27p2 (predicted)
115 Moscovium Mc [Rn]5f146d107s27p3 (predicted)
116 Livermorium Lv [Rn]5f146d107s27p4 (predicted)
117 Tennessine Ts [Rn]5f146d107s27p5 (predicted)

f-Block Elements

The metals in which the additional electron enters (n−2)f orbitals are called inner transition metals. They are also called f-block elements because the extra electrons go to the f-orbitals belonging to (n−2) the main shell.

f-block elements are classified into two categories such as 4f-block and 5f-block elements.

4f Block Metals on the Periodic Table

4f-block elements are also called lanthanides, lanthanones, or rare-earth metals. The first two names are given because their properties resemble lanthanum.

The name rare earth was given because they were extracted from oxides present in the earth and were considered to be rare. Presently, the name rare earth is avoided because many of these elements are no longer rare but are abundant.

Today, ion exchange and solvent extraction processes are used generally for the quick production of highly pure, low-cost rare earth metals. However, the old name is still in use to describe such metals.

Atomic Number Name Symbol Electronic configuration
57 Lanthanum La [Xe]4f05d16s2
58 Cerium Ce [Xe]4f15d16s2
59 Praseodymium Pr [Xe]4f36s2
60 Neodymium Nd [Xe]4f46s2
61 Promethium Pm [Xe]4f56s2
62 Samarium Sm [Xe]4f66s2
63 Europium Eu [Xe]4f76s2
64 Gadolinium Gd [Xe]4f75d16s2
65 Terbium Tb [Xe]4f96s2
66 Dysprosium Dy [Xe]4f106s2
67 Holmium Ho [Xe]4f116s2
68 Erbium Er [Xe]4f126s2
69 Thulium Th [Xe]4f136s2
70 Ytterbium Yb [Xe]4f146s2
71 Lutetium Lu [Xe]4f145d16s2

5f-Block Metals in the Periodic Table

The elements in which the extra electron enters the 5f-orbitals of (n−2) main shell are called 5f-block elements, actinides, or actinones.

The atomic number, name, symbol, and electronic configuration of 5f-block elements are given below,

Atomic number Name Symbol Electronic Configuration
90 Thorium Th [Rn]6d27s2
91 Protactinium Pa [Rn]5f26d17s2
92 Uranium U [Rn]5f36d17s2
93 Neptunium Np [Rn]5f46d17s2
94 Plutonium Pu [Rn]5f67s2
95 Americium Am [Rn]5f77s2
96 Curium Cm [Rn]5f76d17s2
97 Berkelium Bk [Rn]5f97s2
98 Californium Cf [Rn]5f107s2
99 Einsteinium Es [Rn]5f117s2
100 Fermium Fm [Rn]5f127s2
101 Mendelevium Md [Rn]5f137s2
102 Nobelium No [Rn]5f147s2
103 Lawrencium Lr [Rn]5f147s27p1

Properties of Metals

Based on properties, elements present in the periodic table can be divided into two main groups metals and non-metals. The metallic substances generally contain one of three common crystal structures: body-centered cubic (bcc), face-centered cubic (fcc), and hexagonal close-packed (hcp).

For example, chromium, iron, and tungsten contain body-centered cubic crystal structures while aluminum, copper, and gold contain body-centered cubic crystal structures. The hexagonal close-packed crystalline solid is also found in titanium, cobalt, and zinc.

Which element is the most metallic?

The most metallic element found in the periodic table is francium. It is a man-made chemical element because most isotopes of francium are radioactive and they almost instantly decay to form another element.

Therefore, the natural periodic table element that shows the highest metallic character is caesium.

Metallic Bonding

Metallic bonding is a type of chemical bonding that helps to hold metallic atoms together by an electrostatic force of attraction between conduction or delocalized electrons and positively charged metal ions.

The outer electrons in a metal atom can delocalize over the whole metal structure. They are not attached to a particular atom or pair of atoms but they move freely around the whole structure. Therefore, metallic bonding is often called an array of positive ions in a sea of electrons.

The strength of metallic bonds is different for different metallic elements. It reaches a maximum around the middle of the transition metals series because they contain large numbers of delocalized electrons.

Metallic Lustre

In their pure state, most of the metals consist of bright, shining surfaces. This metallic property is called metallic lustre. In other words, metallic luster is a property that describes the amount of light that reflects off the metal.

Metallic elements like gold, silver, and platinum are known for their shining surface. Gold is shining yellow while silver is shining white. Similarly, copper is brown but iron, aluminum, and zinc are lustrous grey.

Hardness of Metal

Most commonly, a metal is hard in nature but the hardness varies from metal to metal. The hardness of metals associated due to mettalic bonding and their crystalline structure.

All the metals except mercury exist as solid in room temperature. However, alkali metals (lithium, sodium, and potassium) are very soft and they can be easily cut with a knife.

Ductility of Metals

A metal is generally ductile in nature. It is the property due to which a metal can be drawn into a thin wire. Gold is the most ductile metal found on Earth.

Malleability Metals

Generally, a metal is malleable in nature. It is the property due to which a metal can be beaten into thin sheets. Gold and silver are the most malleable metallic elements in the periodic table.

Electrical Conductivity

Generally, a metal is a good conductor of electricity in the solid state. However, the conductivity varies from one metal to another. According to the band theory, a conductor contains a partially filled uppermost energy band. Therefore, under an applied field, electrons can move from a partially filled band to vacant sites in the same energy band.

The electrical conductivity of a metal depends not on the number of electrons it has but on the number of vacant levels in an energy band that are available. The conduction of electricity or the flow of electric current in metal occurs due to the flow of free electrons present in the metal.

Semiconductors and nonmetals are relatively poor conductors because they have a very small energy gap between the filled band and the vacant band.

The transition elements copper, silver, and gold consist of an nd10 ns1 electronic configuration. They all contain a filled d energy band but only a half-filled s band. Therefore, vacant sites in the s band are available for electronic movement.

Other transition elements have partially filled d orbitals. Therefore, in the metallic state, they contain partially filled d energy bands. It explains the higher electrical conductivity in transition metals.

Heat Conductivity

The delocalized electrons in metals are highly mobile. Therefore, they are easily able to pass on heat-induced vibrational energy.

Lead and mercury are poor conductors of heat but copper and silver are the best conductors of heat. Therefore, except for lead and mercury, metals are good conductors of heat.

Melting and Boiling Points

The atoms in metals have a strong attractive force between them and much energy is required to overcome it. Therefore, a metal generally has very high melting and boiling points.

Tungsten has the highest melting point among all metals in the periodic table while gallium and cesium have very low melting points. Therefore, gallium and caesium will melt when we keep them in our palms.

Sonority of Metals

The metals that produce a sound on striking hard surfaces are called sonorous. Thus, a metal has been used for making school bells due to its sonorous nature.

Chemical Reactions of Metals

Metals commonly form cations by losing their valence electrons. Therefore, most of the metals present in the periodic table react easily with oxygen, water, and acids.

However, the chemical reactions of metals depend on the reactivity of the metal. For example, alkali and alkaline earth metals show high reactivity and react vigorously with dilute acids, oxygen, and water.

Reaction of Metals with Oxygen

Almost all metals combine with oxygen present in the air to form metal oxides.

Metal + Oxygen → Metal oxide

However, different metals react with oxygen at different rates. For example, sodium (Na) and potassium (K) react vigorously while magnesium (Mg) and aluminum (Al) burn in air only by heating.

Zinc (Zn) burns only on strong heating while iron (Fe) does not burn in the form of a rod or block. Similarly, the metal copper does not burn on heating but blister copper burns.

The noble metals (palladium, platinum, and gold) do not react with oxygen even at high temperatures. However, aluminum forms aluminum oxide when heated in air.

4 Al (s) + 3 O2 (g) → 2 Al2O3 (s)

Similarly, copper combines to form black copper (II) oxide when heated in the presence of oxygen.

2 Cu + O2 → 2 CuO

Properties of Metal Oxides

Generally, metal oxides are basic in nature. However, some metal oxides such as aluminium oxide and zinc oxide show both acidic and basic properties.

Such metal oxides which react with both acids and bases to form salt and water are called amphoteric oxides. Therefore, aluminum oxide and zinc oxide are examples of amphoteric oxides.

Metallic oxides are insoluble in water but alkali metal oxides are dissove in water to form corresponding hydroxides. For example, sodium hydroxide and potassium hydroxide dissove in water to form sodium hydroxide and potassium hydroxide respectively.

Na2O (s) + H2O (l) → 2 NaOH (l)
K2O (s) + H2O (l) → 2 KOH (l)

Reactions of Metal with Water

Generally, a metal reacts with water to form a metal oxide and hydrogen gas. However, the metal oxides which are soluble in water further react with water to form metal hydroxide.

Metal + Water → Metal oxide + Hydrogen gas

Metal oxide + Water → Metal hydroxide

Reaction with Highly Reactive Metals

The highly reactive metallic elements generally react with water to form their hydroxides. However, in the case of sodium and potassium, the reaction is extremely violent and exothermic.

2 K + 2 H2O → 2 KOH + H2 + Heat
2 Na + 2 H2O → 2 NaOH + H2 + Heat

The heat evolved is sufficient for hydrogen to catch fire. Therefore, Na and K are kept in kerosene instead of water.

The alkaline earth metal calcium also reacts violently with water. However, the heat evolved in this reaction is not sufficient for hydrogen to catch fire.

Ca + 2 H2O → Ca(OH)2 + H2

Calcium floats over water because the bubbles of hydrogen gas stick to the surface of the metal.

Reaction with Moderately Reactive Metals

Metallic elements such as aluminum, iron, and zinc do not react either with cold or hot water. Thus, they react with the stream to form a metal oxide and hydrogen gas.

2 Al + 3 H2O → Al2O3 + 3 H2
3 Fe + 4 H2O → Fe3O4 + 4 H2

Reaction with Non-reactive Metals

Lead, copper, silver, and gold do not react with water at all. Therefore, the reactivity order of metallic elements toward water is:

K > Na > Ca > Mg > Al > Fe > Pb > Cu > Ag > Au

Reactions with Acids

Except few less reactive metals, all react with dilute sulfuric acid and hydrochloric acid to produce salt and hydrogen gas.

Metal + Dilute acid → Salt + Hydrogen

Therefore, zinc reacts with dilute hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas

Zn + 2 HCl → ZnCl2 + H2

Due to the strong oxidizing nature of nitric acid, hydrogen gas does not evolve during the reaction of a metal with HNO3. Only magnesium and manganese react with very dilute nitric acid to evolve hydrogen gas.

Metal (Mg/Mn) → Salt + H2

Displacement Reaction of Metals

Reactive metals can displace a comparatively less reactive metal from its compounds in aqueous solution or molten form. The general chemical equation is:

Metal A + Salt of B → Salt of A + Metal B

Cu + 2 AgNO3 → Cu (NO3)2 + 2 Ag

The above type of metallic reaction is called the displacement reaction.

Uses of Metals

Metals are present in nearly all forms of modern life due to their strength, durability, and availability. Iron may be the most common heavy metal used widely in our daily life. Aluminum is the next most commonly light metal used also in many parts of life.

One or more of the essential and trace metals (iron, cobalt, nickel, copper, and zinc) are essential for all higher forms of life. For example, iron is an essential component of hemoglobin and cobalt is an essential component of vitamin B12 (Cobalamin).

The common and most popular uses of metals are included below:

  • Construction industry
  • Electronics
  • Biology and biochemistry
  • Machinery, refractory, and automobiles
  • Decorative products and jewellery
  • Other uses of metals