Assertion: Atomic mass of aluminium is 27 Reason: An atom of aluminium is 27 times heavier than 1/12 the of the mass of the C-12 atom. (a) Assertion and Reason are correct, Reason explains the Assertion. (b) Assertion is correct, Reason is wrong. (c) Assertion is wrong, Reason is correct. The atomic mass of aluminum is 26.98 amu. Aluminum is one of the lightest elements, making it ideal for construction, transportation and other commercial uses. Aluminum is a very common element, third in abundance only to silicon and oxygen. However, aluminum is too reactive to exist in a pure form naturally. Although aluminum is the most abundant metal in the earth's crust, it is never found free in nature. All of the earth's aluminum has combined with other elements to form compounds. Two of the most common compounds are alum, such as potassium aluminum sulfate (KAl(SO 4) 2 12H 2 O), and aluminum oxide (Al 2 O 3). About 8.2% of the earth's crust.
Atomic Number of Aluminium is 13.
Chemical symbol for Aluminium is Al. Number of protons in Aluminium is 13. Atomic weight of Aluminium is 26.9815385 u or g/mol. Melting point of Aluminium is 660,5 °C and its the boiling point is 2467 °C.
» Boiling Point» Melting Point» Abundant» State at STP» Discovery YearAbout Aluminium
This chemical element has got its name from the Latin expression meaning bitter salt. It is the most abundant metal on our planet, valued highly for its high conductivity. Aluminium has excellent ratio of being strong and light, thus it is extensively used in aviation for producing planes and other aircrafts. Aluminium is quite reactive but has high resistance to corrosion by creating a layer of it oxide on the surface. Despite being the most abundant metal, aluminium is rare to be found in its pure form, and usually is produced from bauxites, cryolites, and other minerals. In old times, aluminium used to be considered a precious metal like gold, but for the last century its production technology became was cheaper and common. Industrial uses of this metal are really numerous, and those include automobile, construction, kitchenware and household, food, cosmetics, and other branches.
Uses of Aluminium
Aluminium (or aluminium), lightweight and strong metal with the symbol Al, is extremely used in aircraft, building construction such as skyscrapers, pavilions, sports facilities, as well as in architecture, refrigerators, motor vehicles, solar panels, air conditioners, etc. Empire State Building was the first building in which aluminum was extensively used. Usage of aluminum foil in daily life is very common. It is generally preferred for packaging and cooking. It is also used for heat conductivity, barrier, and electrical conductivity, radiation shield.
Compounds with Aluminium
- Al(OH)3: Aluminium hydroxide
- C6H9AlO6: Aluminium acetate
- NH4ClO4: Aluminum Perchlorate
- LiAlH4: Lithium aluminium hydride
- AlPO4: Aluminium phosphate
- AlCl3: Aluminium chloride (or Aluminum trichloride)
- Al2O3: Aluminum Oxide
- Al2S3: Aluminum Sulfide (or aluminium sulphide)
- AlBr3: Aluminum Bromide
- AlN: Aluminum Nitride
Properties of Aluminium Element
| Atomic Number (Z) | 13 |
|---|---|
| Atomic Symbol | Al |
| Group | 13 |
| Period | 3 |
| Atomic Weight | 26.9815385 u |
| Density | 2.698 g/cm3 |
| Melting Point (K) | 933.47 K |
| Melting Point (℃) | 660,5 °C |
| Boiling Point (K) | 2792 K |
| Boiling Point (℃) | 2467 °C |
| Heat Capacity | 0.897 J/g · K |
| Abundance | 82300 mg/kg |
| State at STP | Solid |
| Occurrence | Primordial |
| Description | Metal |
| Electronegativity (Pauling) χ | 1.61 |
| Ionization Energy (eV) | 5.98577 |
| Atomic Radius | 125pm |
| Covalent Radius | 118pm |
| Valence Electrons | 3 |
| Year of Discovery | 1825 |
| Discoverer | Oersted |
What is the Boiling Point of Aluminium?
Aluminium boiling point is 2467 °C. Boiling point of Aluminium in Kelvin is 2792 K.
What is the Melting Point of Aluminium?
Aluminium melting point is 660,5 °C. Melting point of Aluminium in Kelvin is 933.47 K.
How Abundant is Aluminium?
Abundant value of Aluminium is 82300 mg/kg.
What is the State of Aluminium at Standard Temperature and Pressure (STP)?
State of Aluminium is Solid at standard temperature and pressure at 0℃ and one atmosphere pressure.
When was Aluminium Discovered?
Aluminium was discovered in 1825.
We know, 102 g of Aluminium Oxide (Al2O3) = 6.022 × 1023 molecules of Aluminium Oxide (Al2O3)
The number of Aluminium ions (Al3+) present in one molecule of aluminium oxide is 2.
Therefore, the number of Aluminium ions (Al3+) present in 3.011 × 1020 molecules (0.051 g ) of Aluminium Oxide (Al2O3)
= 6.022 × 1020
This is an answered question from Chapter 3. Atoms And Molecules of CBSE Class 9th Science
Aluminium Mass Number
Check for Complete Exercise Solution for Chapter 3. Atoms And Molecules | CBSE Class 9th Science