Difference between revisions of "Relative Atomic Mass"
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The '''relative atomic mass''' or '''mass number''' of an [[element]] is the number of [[nucleon]]s ([[proton]]s + [[neutron]]s) in an [[atom]]. | The '''relative atomic mass''' or '''mass number''' of an [[element]] is the number of [[nucleon]]s ([[proton]]s + [[neutron]]s) in an [[atom]]. | ||
| − | The '''relative atomic mass''' in [[gram]]s is also the [[mass]] of one [[mole]] or [[ | + | The '''relative atomic mass''' in [[gram]]s is also the [[mass]] of one [[mole]] or [[Avogadro Constant|6.02x10<sup>23</sup>]] [[atom]]s of the [[element]]. |
===About Relative Atomic Mass=== | ===About Relative Atomic Mass=== | ||
| − | : The '''relative atomic mass''' in [[gram]]s on the [[Periodic Table]] tells the [[mass]] of a [[mole]] of the [[element]]. A [[mole]] of the [[element]] is [[ | + | : The '''relative atomic mass''' in [[gram]]s on the [[Periodic Table]] tells the [[mass]] of a [[mole]] of the [[element]]. A [[mole]] of the [[element]] is [[Avogadro Constant|6.02x10<sup>23</sup>]] [[atom]]s of that [[element]]. |
: Two [[atom]]s of the same [[element]] may have the same [[Atomic Number]] but a different [[Relative Atomic Mass]] depending on the number of [[neutron]]s in the [[nucleus]]. [[Element]]s with different '''mass numbers''' are called [[isotope]]s. | : Two [[atom]]s of the same [[element]] may have the same [[Atomic Number]] but a different [[Relative Atomic Mass]] depending on the number of [[neutron]]s in the [[nucleus]]. [[Element]]s with different '''mass numbers''' are called [[isotope]]s. | ||
: The '''relative atomic mass''' is not affected by the number of [[electron]]s. | : The '''relative atomic mass''' is not affected by the number of [[electron]]s. | ||
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|[[File:BoronSymbol.png|center|200px]] | |[[File:BoronSymbol.png|center|200px]] | ||
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| − | | style="height:20px; width:200px; text-align:center;" |[[Hydrogen]] has one [[nucleon]] so it has an '''atomic mass''' of 1 and [[ | + | | style="height:20px; width:200px; text-align:center;" |[[Hydrogen]] has one [[nucleon]] so it has an '''atomic mass''' of 1 and [[Avogadro Constant|6.02x10<sup>23</sup>]] (or 1 [[mole]] of) [[atom]]s of [[Hydrogen]] have a [[mass]] of 1g. |
| − | | style="height:20px; width:200px; text-align:center;" |[[Deuterium]] has two [[nucleon]]s so it has an '''atomic mass''' of 2 and [[ | + | | style="height:20px; width:200px; text-align:center;" |[[Deuterium]] has two [[nucleon]]s so it has an '''atomic mass''' of 2 and [[Avogadro Constant|6.02x10<sup>23</sup>]] (or 1 [[mole]] of) [[atom]]s of [[Deuterium]] have a [[mass]] of 2g. |
| − | | style="height:20px; width:200px; text-align:center;" |[[Tritium]] has three [[nucleon]]s so it has an '''atomic mass''' of 3 and [[ | + | | style="height:20px; width:200px; text-align:center;" |[[Tritium]] has three [[nucleon]]s so it has an '''atomic mass''' of 3 and [[Avogadro Constant|6.02x10<sup>23</sup>]] (or 1 [[mole]] of) [[atom]]s of [[Tritium]] have a [[mass]] of 3g. |
| − | | style="height:20px; width:200px; text-align:center;" |[[Boron]] has eleven [[nucleon]]s so it has an '''atomic mass''' of 11 and [[ | + | | style="height:20px; width:200px; text-align:center;" |[[Boron]] has eleven [[nucleon]]s so it has an '''atomic mass''' of 11 and [[Avogadro Constant|6.02x10<sup>23</sup>]] (or 1 [[mole]] of) [[atom]]s of [[Boron]] have a [[mass]] of 11g. |
|} | |} | ||
Revision as of 11:43, 29 October 2019
Contents
Key Stage 3
Meaning
An element tile showing the mass number.
The Atomic Mass or mass number is the number of nucleons (protons + neutrons) in an atom.
About The Atomic Mass
- Two atoms of the same element may have the same Atomic Number but a different Atomic Mass depending on the number of neutrons in the nucleus. Elements with different mass numbers are called isotopes.
- The atomic mass is not affected by the number of electrons.
- Only the particles in the nucleus affect the atomic mass.
Examples
| Hydrogen | Helium | Lithium | Beryllium |
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| Hydrogen has one nucleon so it has an atomic mass of 1. | Helium has four nucleons so it has an atomic mass of 4. | Lithium has seven nucleons so it has an atomic mass of 7. | Beryllium has nine nucleons so it has an atomic mass of 9. |
Key Stage 4
Meaning
An element tile showing the mass number.
The relative atomic mass or mass number of an element is the number of nucleons (protons + neutrons) in an atom.
The relative atomic mass in grams is also the mass of one mole or 6.02x1023 atoms of the element.
About Relative Atomic Mass
- The relative atomic mass in grams on the Periodic Table tells the mass of a mole of the element. A mole of the element is 6.02x1023 atoms of that element.
- Two atoms of the same element may have the same Atomic Number but a different Relative Atomic Mass depending on the number of neutrons in the nucleus. Elements with different mass numbers are called isotopes.
- The relative atomic mass is not affected by the number of electrons.
- Only the particles in the nucleus affect the relative atomic mass.
Examples
| Hydrogen | Deuterium | Tritium | Boron |
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| Hydrogen has one nucleon so it has an atomic mass of 1 and 6.02x1023 (or 1 mole of) atoms of Hydrogen have a mass of 1g. | Deuterium has two nucleons so it has an atomic mass of 2 and 6.02x1023 (or 1 mole of) atoms of Deuterium have a mass of 2g. | Tritium has three nucleons so it has an atomic mass of 3 and 6.02x1023 (or 1 mole of) atoms of Tritium have a mass of 3g. | Boron has eleven nucleons so it has an atomic mass of 11 and 6.02x1023 (or 1 mole of) atoms of Boron have a mass of 11g. |