Question

Lithium has ______ valence electrons. Sulfur has _____ valence electrons. These chemicals will likely combine in a ratio of ____ Li atoms to _____ sulfur atoms.

Options:
a. 1; 6; 1; 1
b. 1; 6; 1; 2
c. 1; 6; 2; 1
d. 2; 6; 1; 1

Answer 1

Lithium has one valence electron and sulfur has six. They combine in a ratio of two lithium atoms to one sulfur atom, forming Li₂S. Thus, option a is correct.

Step-by-step explanation:

Lithium (Li) has an atomic number of 3 and an electron configuration of 1s²2s¹, which means it has one valence electron. Sulfur (S), on the other hand, has an atomic number of 16, and its electron configuration ends with 3s² 3p´, thus having six valence electrons. To achieve a stable electron configuration similar to the nearest noble gas, lithium needs to lose one electron, and sulfur needs two electrons to fill its valence shell. Therefore, it takes two lithium atoms to donate two electrons, one for each atom, to combine with one sulfur atom that can accept these two electrons, forming the stable ionic compound Li₂S. The correct combination is two lithium atoms to one sulfur atom, making the answer: a. 1; 6; 2; 1.

Answer 2

Lithium has one valence electron while sulfur has six valence electrons. They will combine in a ratio of 2 Li atoms to 1 sulfur atom, forming Li2S.

Step-by-step explanation:

Lithium has one valence electron. This can be determined by its electron configuration of 1s²2s¹, indicating that there is only one electron in its valence shell. Sulfur, on the other hand, has six valence electrons, which aligns with its position in Group 16 of the periodic table (also known as the oxygen family). In order to achieve a full valence shell, sulfur typically gains two electrons to fill up its shell, while lithium tends to lose one electron to achieve a full shell like the noble gases.

From this understanding, it becomes clear that two lithium atoms will combine with one sulfur atom to form a stable compound. This is because each lithium atom can donate one electron to sulfur, filling sulfur's valence shell without any surplus electrons remaining. Therefore, the chemicals will likely combine in a ratio of 2 Li atoms to 1 sulfur atom, accurately represented by the formula Li2S.