How do you determine the number of valence electrons in one atom of each of the following elements. ... We had 20 elements overall for homework so I listed the first 5
A) Na
B.) F
C.) Rb
D.) Ba
E.) I
To determine the number of valence electrons in an atom, you need to look at the electron configuration of the element.
A) Sodium (Na)
Sodium has an atomic number of 11. The electron configuration of sodium is 1s² 2s² 2p⁶ 3s¹. The outermost shell, also known as the valence shell, is the third shell (3s). Therefore, sodium (Na) has 1 valence electron.
B) Fluorine (F)
Fluorine has an atomic number of 9. The electron configuration of fluorine is 1s² 2s² 2p⁵. The outermost shell is the second shell (2p). Therefore, fluorine (F) has 7 valence electrons.
C) Rubidium (Rb)
Rubidium has an atomic number of 37. The electron configuration of rubidium is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹. The outermost shell is the fifth shell (5s). Therefore, rubidium (Rb) has 1 valence electron.
D) Barium (Ba)
Barium has an atomic number of 56. The electron configuration of barium is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s². The outermost shell is the sixth shell (6s). Therefore, barium (Ba) has 2 valence electrons.
E) Iodine (I)
Iodine has an atomic number of 53. The electron configuration of iodine is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁵. The outermost shell is the fifth shell (5p). Therefore, iodine (I) has 7 valence electrons.
Remember, the valence electrons are the electrons in the outermost shell of an atom, which determine the chemical properties of an element.