how many valence electrons are in a neutral lithium atom?
How many valence electrons are in a neutral lithium atom?
Answer:
Valence electrons are the electrons in the outermost shell of an atom that are involved in chemical bonding. To determine the number of valence electrons in a neutral lithium atom, we need to look at its electron configuration.
Electron Configuration of Lithium
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Atomic Number of Lithium:
- A neutral lithium atom has an atomic number of 3, which means it has 3 protons and, correspondingly, 3 electrons.
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Electron Configuration:
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The electron configuration of lithium follows the order of filling of atomic orbitals. The configuration is given by distributing the electrons in the increasing order of energy levels.
For lithium:
- The first two electrons fill the 1s orbital.
- The third electron goes into the next available orbital, which is the 2s orbital.
Thus, the electron configuration for lithium can be written as:
1s^2 2s^1
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Valence Electrons:
- Valence electrons are located in the outermost shell of the atom. For lithium, the outermost shell is the 2s orbital which contains 1 electron.
Conclusion:
Therefore, a neutral lithium atom has 1 valence electron.
By understanding the concept of electron configuration, one can systematically determine the number of valence electrons present in any atom. For lithium:
- The electron configuration is 1s^2 2s^1.
- The single electron in the 2s orbital is the valence electron.
Final Answer:
A neutral lithium atom has 1 valence electron.