An element is the simplest type of matter that cannot be split into less complicated substances or developed from simpler substances by any type of ordinary usmam.orgical or physical method. There room 110 elements known to us, out of which 92 are normally occurring, if the rest have been prepared artificially. Elements are further classified into metals, non-metals, and metalloids.
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| Distinguishing luster (shine) | Non-lustrous, various colors |
| Malleable and also ductile (flexible) as solids | Brittle, difficult or soft |
| Conduct heat and also electricity | Poor conductors |
| Metallic oxides are basic, ionic | Nonmetallic oxides room acidic, compounds |
| Cations in aqueous solution | Anions, oxyanions in aqueous solution |
Metals
All elements except hydrogen, which kind positive ion by losing electrons throughout usmam.orgical reactions are referred to as metals. Therefore metals room electropositive elements. They are characterized by bright luster, hardness, ability to resonate sound and also are fantastic conductors of heat and also electricity. Steels are solids under normal conditions except for Mercury.
Physical nature of Metals
Metals room lustrous, malleable, ductile, good conductors of heat and electricity. Other properties include:
State: metals are solids in ~ room temperature with the exemption of mercury, which is fluid at room temperature (Gallium is liquid on hot days). Luster: Metals have actually the top quality of reflecting light native its surface and also can be sleek e.g., gold, silver and copper. Malleability: Metals have the ability to withstand hammering and also can be made right into thin sheets well-known as foils (a sugar cube chunk that gold have the right to be pounded into a slim sheet which will certainly cover a football field). Ductility: Metals have the right to be drawn into wires. 100 gm that silver can be drawn into a slim wire around 200 meter long. Hardness: All steels are hard other than sodium and potassium, which are soft and also can be reduced with a knife. Valency: Metals have 1 to 3 electrons in the outermost shell of their atoms. Conduction: steels are great conductors due to the fact that they have complimentary electrons. Silver and copper are the two ideal conductors the heat and also electricity. Command is the poorest conductor of heat. Bismuth, mercury and also iron are additionally poor conductors Density: Metals have actually high density and are really heavy. Iridium and osmium have the highest densities where as lithium has the shortest density. Melting and also Boiling Points: Metals have actually high melting and boiling point. Tungsten has actually the highest possible melting suggest where as silver has low boiling point. Sodium and potassium have low melting points.usmam.orgical nature of Metals
Metals are electropositive aspects that generally form basic or amphoteric oxides with oxygen. Other usmam.orgical nature include:
Electropositive Character: metals tend to have low ionization energies, and also typically shed electrons (i.e. Are oxidized) as soon as they undergo usmam.orgical reactions They normally do no accept electrons. Because that example:Metal oxide + water -> steel hydroxide
Na2O(s) + H2O(l) -> 2NaOH(aq)
CaO(s) + H2O(l) -> Ca(OH)2(aq)
metal oxides exhibit their basic usmam.orgistry nature by reacting with acids to type salts and also water:Metal oxide + mountain -> salt + water
MgO(s) + HCl(aq) -> MgCl2(aq) + H2O(l)
NiO(s) + H2SO4(aq) -> NiSO4(aq) + H2O(l)
Example
What is the usmam.orgical formula for aluminum oxide?
Solution
Al has 3+ charge, the oxide ion is O2-, hence Al2O3
Example
Would you suppose it to be solid, fluid or gas at room temp?
Solutions
Oxides of metals are characteristically solid at room temp
Example
Write the balanced usmam.orgical equation because that the reaction the aluminum oxide v nitric acid:
Solution
Metal oxide + mountain -> salt + water
Al2O3(s) + 6HNO3(aq) -> 2Al(NO3)3(aq) + 3H2O(l)
Nonmetals
Elements that tend to gain electrons to kind anions during usmam.orgical reactions are dubbed non-metals. These are electronegative elements. They room non-lustrous, brittle and poor conductors that heat and electricity (except graphite). Non-metals deserve to be gaseous, liquids or solids.
Physical nature of nonmetals:
Physical State: many of the non-metals exist in 2 of the three claims of matter at room temperature: gases (oxygen) and solids (carbon). Non-Malleable and Ductile: Non-metals are very brittle, and cannot it is in rolled into wires or pounded right into sheets. Conduction: castle are poor conductors the heat and also electricity. Luster: These have actually no metallic luster and also do no reflect irradiate Conductivity: negative conductors that heat and electricity Melting and also Boiling Points: The melting points that non-metals are generally lower than steels Seven non-metals exist under standard conditions as diatomic molecules: H2(g) N2(g) O2(g) F2(g) Cl2(g) Br2(l) I2(l) (volatile liquid - evaporates readily)usmam.orgical properties of Nonmetals
Non-metals have a tendency to acquire or share electron with various other atoms. They are electronegative in character. Nonmetals, when reacting with metals, tend to gain electrons (typically attaining noble gas electron configuration) and become anions:Nonmetal + metal -> Salt
<3Br_2(l) + 2Al_(s) ightarrow 2AlBr_3(s)>
compounds composed totally of nonmetals are molecular building materials (not ionic). They generally form acidic or neutral oxides through oxygen the that dissolve in water reaction to type acids:Nonmetal oxide + water -> acid
(carbonated water is contempt acidic)
Nonmetal oxides can combine with bases to form salts.Nonmetal oxide + basic -> salt
Metalloids
Properties intermediate in between the metals and also nonmetals. Metalloids are advantageous in the semiconductor industry.
| Gold | Oxygen | Silicon |
| Silver | Carbon | Boron |
| Copper | Hydrogen | Arsenic |
| Iron | Nitrogen | Antimony |
| Mercury | Sulphur | Germanium |
| Zinc | Phosphorus |
Physical nature of Metalloids
State: They room all solid in ~ room temperature. Conduction: part metalloids, such as silicon and also germanium, have the right to act as electrical conductors under the best conditions, for this reason they are referred to as semi-conductors.Luster: Silicon for example appears lustrous, but is not simple or ductile (it is brittle - a characteristics of some nonmetals). The is a much poorer conductor of heat and also electricity 보다 the metals.
Solid Solutions: castle can form alloys with various other metals.usmam.orgical properties of Metalloids
your physical properties have tendency to be metallic, however their usmam.orgistry properties have tendency to be non-metallic. The oxidation number of an aspect in this team can selection from +3 to -2, depending upon the team in which that is located.See more: How Many Perpendicular Lines Does A Hexagon With 1 Pair Of Perpendicular Sides
Trends in Metallic and Nonmetallic Character
Metallic character is strongest for the aspects in the leftmost part of the regular table, and also tends come decrease together we move to the right in any duration (nonmetallic character increases with boosting ionization values). Within any kind of group of aspects (columns), the metallic character rises from optimal to bottom (the ionization values typically decrease together we move down a group). This general trend is not have to observed v the transition metals.