State the number of valence electrons for a hydrogen atom and a chlorine atom_ 3. State the number of valence electrons for & sodium ion and a chloride ion in an ionic bond. 4. State the number of valence electrons for a hydrogen atom and chlorine atom in a covalent bond.
The Correct Answer and Explanation is:
Answers:
- A hydrogen atom has 1 valence electron.
- A chlorine atom has 7 valence electrons.
- A sodium ion (Na⁺) has 0 valence electrons, and a chloride ion (Cl⁻) has 8 valence electrons.
- In a covalent bond, both the hydrogen atom and the chlorine atom share 1 electron each, allowing both to achieve a stable electron configuration.
Explanation
Valence electrons are the outermost electrons of an atom and are crucial in determining how atoms interact with one another through chemical bonding. The number of valence electrons influences whether an atom will form ionic or covalent bonds.
Hydrogen has only one electron, and that electron resides in the first and only shell of the atom, making it its single valence electron. Chlorine, on the other hand, has seventeen electrons. The first two shells are filled with two and eight electrons respectively, and the remaining seven electrons go into the third shell, which is the outermost shell for chlorine. This gives chlorine seven valence electrons.
In an ionic bond, atoms transfer electrons to achieve full outer shells. Sodium (Na) has one valence electron in its outer shell. When sodium loses this electron, it becomes a positively charged ion (Na⁺) and is left with a full second shell, resembling the electron configuration of neon. Since the outermost shell is now full, it has zero valence electrons. Chlorine gains the electron lost by sodium, becoming a negatively charged ion (Cl⁻). This gives chlorine a complete outer shell of eight electrons, making it stable with eight valence electrons.
In a covalent bond, atoms share electrons instead of transferring them. A hydrogen atom, which needs one more electron to complete its shell, shares its single electron with a chlorine atom, which needs one electron to complete its octet. Through this sharing, both atoms achieve stable configurations. Hydrogen reaches the duet rule with two electrons in its shell, and chlorine completes its octet. This type of sharing of electrons is the basis of covalent bonding, and it allows both atoms to remain neutral while achieving greater stability.
