the atomic number of lithium (li) is 3, and the atomic number of oxygen (o) is 8. what is the formula of the…

the atomic number of lithium (li) is 3, and the atomic number of oxygen (o) is 8. what is the formula of the compound formed by the combination of lithium and oxygen?\na. lio₂\nb. li₂o\nc. li₃o₈\nd. li₇o₁₆

the atomic number of lithium (li) is 3, and the atomic number of oxygen (o) is 8. what is the formula of the compound formed by the combination of lithium and oxygen?\na. lio₂\nb. li₂o\nc. li₃o₈\nd. li₇o₁₆

Answer

Explanation:

Step1: Determine the valency of lithium

Lithium has an atomic number of 3. Its electron - configuration is 2, 1. It loses 1 electron to achieve a stable configuration, so its valency is +1.

Step2: Determine the valency of oxygen

Oxygen has an atomic number of 8. Its electron - configuration is 2, 6. It gains 2 electrons to achieve a stable configuration, so its valency is - 2.

Step3: Find the formula of the compound

To form a neutral compound, the total positive charge must equal the total negative charge. Let the formula of the compound be $Li_xO_y$. Then $x\times(+ 1)+y\times(-2)=0$. Cross - multiplying gives $x = 2y$. The simplest whole - number ratio is when $x = 2$ and $y = 1$. So the formula is $Li_2O$.

Answer:

B. $Li_2O$