There are 8.61 × 10²⁰ atoms in 0.290 g P₂O₅.
Step 1. Convert <em>grams of P₂O₅ to moles of P₂O₅</em>.
Step 2. Convert <em>moles of P₂O₅ to molecules of P₂O₅</em>.
Step 3. Convert <em>molecules of P₂O₅ to atoms</em>.
There are seven atoms in 1 mol P₂O₅.
∴ 
Answer:
12.50g
Explanation:
T½ = 2.5years
No = 100g
N = ?
Time (T) = 7.5 years
To solve this question, we'll have to find the disintegration constant λ first
T½ = In2 / λ
T½ = 0.693 / λ
λ = 0.693 / 2.5
λ = 0.2772
In(N/No) = -λt
N = No* e^-λt
N = 100 * e^-(0.2772*7.5)
N = 100*e^-2.079
N = 100 * 0.125
N = 12.50g
The sample remaining after 7.5 years is 12.50g
Answer:
photo is blurred plese send photo clearly
7 valence electrons in an atom
I think it is with screens l, chemicals, and filters
I hope this helped
