What is the correct formula for the ionic compound that would result from the combination of sodium and phosphorus?
A. $Na _3 P$
B. $Na _3 Ph$
C. $NaP _3$
D. $S _3 P$
Answer (1)
Sodium (Na) forms a +1 ion ( N a + ).
Phosphorus (P) forms a -3 ion ( P 3 − ).
To balance the charges, three N a + ions are needed for every one P 3 − ion.
The chemical formula for the ionic compound is N a 3 P .
Explanation
Understanding the Problem We want to determine the correct chemical formula for the ionic compound formed between sodium (Na) and phosphorus (P). To do this, we need to consider the charges of the ions formed by each element and find the ratio that results in a neutral compound.
Determining the Charge of Sodium Ion Sodium (Na) is in Group 1 of the periodic table, which means it tends to lose one electron to achieve a stable electron configuration. Therefore, sodium forms a +1 ion, written as N a + .
Determining the Charge of Phosphorus Ion Phosphorus (P) is in Group 15 of the periodic table. It tends to gain three electrons to achieve a stable electron configuration. Therefore, phosphorus forms a -3 ion, written as P 3 − .
Balancing the Charges To form a neutral compound, the total positive charge must equal the total negative charge. We need to find the smallest whole number ratio of N a + and P 3 − ions that will balance the charges.
Finding the Correct Ratio To balance the charges, we need three sodium ions ( N a + ) for every one phosphorus ion ( P 3 − ). This is because 3(+1) + 1(-3) = 3 - 3 = 0.
Writing the Chemical Formula The chemical formula for the ionic compound is written with the cation (positive ion) first, followed by the anion (negative ion). Subscripts are used to indicate the number of each ion in the formula. In this case, we have three sodium ions ( N a ) and one phosphorus ion ( P ). Therefore, the formula is N a 3 P .
Final Answer The correct formula for the ionic compound formed from sodium and phosphorus is N a 3 P .
Examples
Ionic compounds like N a 3 P are crucial in various applications. For instance, understanding the formation of such compounds helps in designing fertilizers, where phosphorus is essential for plant growth. The correct ratio of elements ensures that the compound is stable and effective. Similarly, in materials science, knowing how elements combine ionically allows for the creation of new materials with specific properties, such as conductivity or hardness. This knowledge is also vital in environmental science, where the behavior of ionic compounds affects soil and water quality.
