Final answer:
The electron configurations for the atoms in each pair are obtained by using the noble gas notation. The ratio of atoms in the ionic compound formed between Al and F is 1:3. The ratio of atoms in the ionic compound formed between Li and O is 2:1. The ratio of atoms in the ionic compound formed between Be and Se is 1:1.
Step-by-step explanation:
The electron configuration of an atom is a representation of the arrangement of electrons in its orbitals. To write the electron configuration, we use the periodic table as a reference. The abbreviated form of the electron configuration is obtained by using the noble gas notation, where the electron configuration of the noble gas closest to the element is written within square brackets followed by the configuration of the remaining electrons.
a. The electron configuration for aluminum (Al) is [Ne] 3s2 3p1 and for fluorine (F) is [He] 2s2 2p5. To determine the ratio of atoms in the ionic compound formed between Al and F, we need to consider their charges. Aluminum forms a 3+ cation (Al3+) while fluorine forms a 1- anion (F-). The ratio of Al to F in the ionic compound is 1:3.
b. The electron configuration for lithium (Li) is [He] 2s1 and for oxygen (O) is [He] 2s2 2p4. Lithium forms a 1+ cation (Li+) while oxygen forms a 2- anion (O2-). The ratio of Li to O in the ionic compound is 2:1.
c. The electron configuration for beryllium (Be) is [He] 2s2 and for selenium (Se) is [Ar] 3d10 4s2 4p4. Beryllium forms a 2+ cation (Be2+) while selenium forms a 2- anion (Se2-). The ratio of Be to Se in the ionic compound is 1:1.
d. None of the above options are the correct answer for this question.