Question

use the periodic table to answer the question
which statement best describes the arrangement of electrons in an atom of fluorine (f)?
(1 point)
○ there are two electrons in the first energy level and seven electrons in the second energy level
○ there are seven electrons in the first energy level and two electrons in the second energy level
○ there are two electrons in the first energy level and five electrons in the second energy level
○ there are five electrons in the first energy level and two electrons in the second energy level

Explanation:

1. First, recall the atomic number of fluorine (F) from the periodic table, which is 9. The atomic number equals the number of electrons in a neutral atom, so a fluorine atom has 9 electrons.
2. The electron configuration follows the rules of energy levels (shells). The first energy level (n=1) can hold a maximum of 2 electrons, and the second energy level (n=2) can hold a maximum of 8 electrons.
3. For fluorine (9 electrons): Fill the first energy level with 2 electrons. Then, the remaining electrons are \( 9 - 2 = 7 \), which go into the second energy level.
4. Now, analyze the options:

• Option 1: "There are two electrons in the first energy level and seven electrons in the second energy level" matches our calculation (2 in n=1, 7 in n=2).
• Option 2: 7 in first and 2 in second is incorrect (first level can only hold 2).
• Option 3: 2 in first and 5 in second would total 7 electrons, but fluorine has 9, so incorrect.
• Option 4: 5 in first and 2 in second is incorrect (first level max is 2, and total electrons would be 7, not 9).

Answer:

There are two electrons in the first energy level and seven electrons in the second energy level (the first option among the given choices).