Question

how many atoms of p are present in a sample of p₂o₅ that contains 5.2 × 10²³ atoms o? 6.4 × 10²³ atoms of p; 2.1 × 10²³ atoms of p; 9.3 × 10²³ atoms of p; 4.6 × 10²³ atoms of p

Explanation:

Step1: Determine the ratio of P to O in \( P_2O_5 \)

In \( P_2O_5 \), the ratio of P atoms to O atoms is \( 2:5 \) (2 P atoms for every 5 O atoms).

Step2: Set up a proportion to find the number of P atoms

Let \( x \) be the number of P atoms. The proportion is \( \frac{2}{5}=\frac{x}{5.2\times10^{23}} \).
To solve for \( x \), cross - multiply: \( 5x = 2\times(5.2\times10^{23}) \)
\( 5x=10.4\times10^{23} \)
Then, divide both sides by 5: \( x=\frac{10.4\times10^{23}}{5} \)
\( x = 2.08\times10^{23}\approx2.1\times10^{23} \)

Answer:

2.1 x 10²³ atoms of P