All of the following are the properties of metal except:
a) Solid
b) Ductile
c) Malleable
d) Non Conducting
Answers
Answer:
Metals are lustrous, malleable, ductile, good conductors of heat and electricity. Other properties include:
State: Metals are solids at room temperature with the exception of mercury, which is liquid at room temperature (Gallium is liquid on hot days).
Luster: Metals have the quality of reflecting light from its surface and can be polished e.g., gold, silver and copper.
Malleability: Metals have the ability to withstand hammering and can be made into thin sheets known as foils (a sugar cube chunk of gold can be pounded into a thin sheet which will cover a football field).
Ductility: Metals can be drawn into wires. 100 gm of silver can be drawn into a thin wire about 200 meters long.
Hardness: All metals are hard except sodium and potassium, which are soft and can be cut with a knife.
Valency: Metals have 1 to 3 electrons in the outermost shell of their atoms.
Conduction: Metals are good conductors because they have free electrons. Silver and copper are the two best conductors of heat and electricity. Lead is the poorest conductor of heat. Bismuth, mercury and iron are also poor conductors
Density: Metals have high density and are very heavy. Iridium and osmium have the highest densities where as lithium has the lowest density.
Melting and Boiling Points: Metals have high melting and boiling point. Tungsten has the highest melting point where as silver has low boiling point. Sodium and potassium have low melting points.
Chemical Properties of Metals
Metals are electropositive elements that generally form basic or amphoteric oxides with oxygen. Other chemical properties include:
Electropositive Character: Metals tend to have low ionization energies, and typically lose electrons (i.e. are oxidized) when they undergo chemical reactions They normally do not accept electrons. For example:
Na0→Na++e−(2.11.1)
Mg0→Mg2++2e−(2.11.2)
Al0→Al3++3e−(2.11.3)
Alkali metals are always 1+ (lose the electron in s subshell)
Alkaline earth metals are always 2+ (lose both electrons in s subshell)
Transition metal ions do not follow an obvious pattern, 2+ is common, and 1+ and 3+ are also observed
Compounds of metals with non-metals tend to be ionic in nature
Most metal oxides are basic oxides and dissolve in water to form metal hydroxides:
Metal oxide + water -> metal hydroxide
Na2O(s) + H2O(l) -> 2NaOH(aq)
CaO(s) + H2O(l) -> Ca(OH)2(aq)
Metal oxides exhibit their basic chemical nature by reacting with acids to form salts and water:
Metal oxide + acid -> salt + water
MgO(s) + HCl(aq) -> MgCl2(aq) + H2O(l)
NiO(s) + H2SO4(aq) -> NiSO4(aq) + H2O(l)
Example
What is the chemical formula for aluminum oxide?
H2(g)
N2(g)
O2(g)
F2(g)
Cl2(g)
Br2(l)
I2(l) (volatile liquid - evaporates readily)
Chemical Properties of Nonmetals
Non-metals have a tendency to gain or share electrons with 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
3Br2(l)+2Al(s)→2AlBr3(s)(2.11.4)
Compounds composed entirely of nonmetals are molecular substances (not ionic).
They generally form acidic or neutral oxides with oxygen that that dissolve in water react to form acids:
Nonmetal oxide + water -> acid
CO2(g)+H2O(l)→H2CO3(aq)carbonic acid(2.11.5)
(carbonated water is slightly acidic)
Nonmetal oxides can combine with bases to form salts.
Nonmetal oxide + base -> salt
CO2(g)+2NaOH(aq)→Na2CO3(aq)+H2O(l)(2.11.6)
Metalloids
Properties intermediate between the metals and nonmetals. Metalloids are useful in the semiconductor industry.
Gold
Oxygen
Silicon
Silver
Carbon
Boron
Copper
Hydrogen
Arsenic
Iron
Nitrogen
Antimony
Mercury
Sulphur
Germanium
Zinc
Phosphorus
Physical Properties of Metalloids
State: They are all solid at room temperature.
Conduction: Some metalloids, such as silicon and germanium, can act as electrical conductors under the right conditions, thus they are called semi-conductors.
Luster: Silicon for example appears lustrous, but is not malleable or ductile (it is brittle - a characteristic of some nonmetals). It is a much poorer conductor of heat and electricity than the metals.
Solid
The correct option is d.
- Solid: All the metals are hard and exist as a solid. For example, iron, gold, silver, copper all metals are all solid.
- .Ductile: Metals can be broken down in wire. So, it is ductile. For example, silver can be broken down into silver wire.
- Malleable: All the metals can not be cut by a knife. We need a hammer to break it. So, this is malleable.
- Conductivity: Metals are highly conductive of heat and electricity due to the presence of free electrons in them. So, non conducting is not a property of metal.