Carbon is a chemical element with atomic number 6 which means there are 6 protons in its nucleus. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs. Carbon (6 C) has 15 known isotopes, from 8 C to 22 C, of which 12 C and 13 C are stable.The longest-lived radioisotope is 14 C, with a half-life of 5,730 years. This is also the only carbon radioisotope found in nature—trace quantities are formed cosmogenically by the reaction 14 N + 1 n → 14 C + 1 H. The term 'atomic mass' refers to the mass of a single atom. The mass of a single atom of carbon-12 is defined as exactly 12 u. The term atomic mass is also often used (though technically, incorrectly) to refer to the average atomic mass of all of the isotopes of an element. This second definition is actually the relative atomic mass of an element — a single average value of the element's.
Atomicity is defined as the total number of atoms present in a molecule. For example, each molecule of oxygen (O2) is composed of two oxygen atoms. So atomicity of oxygen is 2.[1]In older contexts, the term atomicity is sometimes used in the same sense as valency.
On the basis of atomicity, molecules can be classified as:
Atomic No Of Carbon
- Monatomic – composed of 1 atom e.g. He, Ne, Ar (all noble gases are monatomic)
- Diatomic – composed of 2 atoms e.g. H2 , N2 , O2
- Triatomic – composed of 3 atoms e.g. O3
- Polyatomic – composed of 3 or more atoms e.g. P4 , S8
All metals and some other elements, such as carbon, do not have a simple structure but consist of a very large and indefinite number of atoms bonded together. Their atomicity cannot be determined and is usually considered as 1.
Atomicity may vary in different allotropes of the same element.
Examples[edit]
All metals and some other elements, such as carbon, do not have a simple structure but consist of a very large and indefinite number of atoms bonded together. Their atomicity cannot be determined and is usually considered as 1.
Atomicity may vary in different allotropes of the same element.
Examples[edit]
The atomicity of the first 31 elements in the periodic table is as follows:
| Atomic Number | Element | Atomicity |
|---|---|---|
| 1 | Hydrogen | 2 |
| 2 | Helium | 1 |
| 3 | Lithium | 1 |
| 4 | Beryllium | 1 |
| 5 | Boron | 1* |
| 6 | Carbon | 1 |
| 7 | Nitrogen | 2 |
| 8 | Oxygen | 2 |
| 9 | Fluorine | 2 |
| 10 | Neon | 1 |
| 11 | Sodium | 1 |
| 12 | Magnesium | 1 |
| 13 | Aluminium | 1 |
| 14 | Silicon | 1** |
| 15 | Phosphorus | 4 |
| 16 | Sulphur | 8 |
| 17 | Chlorine | 2 |
| 18 | Argon | 1 |
| 19 | Potassium | 1 |
| 20 | Calcium | 1 |
| 21 | Scandium | 1 |
| 22 | Titanium | 1 |
| 23 | Vanadium | 1 |
| 24 | Chromium | 1 |
| 25 | Manganese | 1 |
| 26 | Iron | 1 |
| 27 | Cobalt | 1 |
| 28 | Nickel | 1 |
| 29 | Copper | 1 |
| 30 | Zinc | 1 |
| 31 | Gallium | 1 |
| * Boron has too many allotropes. | ||
| ** Silicon forms network lattice. |
References[edit]
- ^Determination of Chlorine in Oxygen From Solid Chemical Oxygen Generators, SAE International, doi:10.4271/arp1320
Carbon Atom Diagram
Study of atomicity
