Textbook Question
Determine the number of valence electrons in each element. a. Cl b. In c. C d. As
10. Periodic Properties of the Elements
Valence Electrons of Elements
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
How many valence electrons are present in an atom of chlorine (Cl)?
A
5
B
8
C
6
D
7
Verified step by step guidance1
First, identify the atomic number of chlorine (Cl) from the periodic table. Chlorine has an atomic number of 17, which means it has 17 electrons in a neutral atom.
Next, understand the electron configuration of chlorine. Electrons fill orbitals in a specific order: 1s, 2s, 2p, 3s, 3p, etc. Chlorine's electron configuration is: \(1s^2 2s^2 2p^6 3s^2 3p^5\).
Valence electrons are the electrons in the outermost shell of an atom. For chlorine, the outermost shell is the third shell, which contains the 3s and 3p orbitals.
Count the electrons in the outermost shell (third shell) of chlorine. The 3s orbital has 2 electrons and the 3p orbital has 5 electrons, totaling \(2 + 5 = 7\) valence electrons.
Conclude that chlorine has 7 valence electrons, which are responsible for its chemical properties and reactivity.
2:32mWatch next
Master Main Group Elements Valence Electrons with a bite sized video explanation from Jules
Start learningRelated Videos
Related Practice
Valence Electrons of Elements practice set
Problem sets built by lead tutorsExpert video explanations