Answer: To determine the electron arrangements for elements A (atomic number 6) and B (atomic number 9), we need to know how electrons are distributed in their electron shells. The electron arrangement is represented by the electron configuration.
The electron configuration is typically written in the format of numbers and letters, where the numbers represent the principal energy levels (shells) and the letters (s, p, d, f) represent the subshells within those energy levels. Each subshell can hold a specific number of electrons.
Let's determine the electron arrangements for elements A and B:
Element A (Atomic number 6):
Atomic number 6 means that element A has 6 electrons.
The electron configuration for carbon (element A) is: 1s² 2s² 2p²
Here's how it works:
The first shell (1s) can hold 2 electrons, so we place 2 electrons in the 1s subshell.
The second shell (2s and 2p) can hold 8 electrons. In this case, we fill the 2s subshell with 2 electrons and place 4 electrons in the 2p subshell (2 in one p orbital and 2 in another).
Element B (Atomic number 9):
Atomic number 9 means that element B has 9 electrons.
The electron configuration for fluorine (element B) is: 1s² 2s² 2p⁵
Here's how it works:
The first shell (1s) can hold 2 electrons, so we place 2 electrons in the 1s subshell.
The second shell (2s and 2p) can hold 8 electrons. We fill the 2s subshell with 2 electrons, and in this case, we place 5 electrons in the 2p subshell (1 in one p orbital and 2 in each of the other two p orbitals).
In summary:
- Element A (Atomic number 6, carbon) has the electron configuration: 1s² 2s² 2p²
- Element B (Atomic number 9, fluorine) has the electron configuration: 1s² 2s² 2p⁵