Answer:
The number of valence electrons determines an element's reactivity, or how likely the element is to react with other elements.
Explanation:
The percentage abundance is a measure of ratio of the number of each isotope and the total number of the element. The percentage abundance of each isotope is :
- Le - 19 = 0.32
- Le - 17 = 0.44
- Le - 15 = 0.24
Number of each isotope in the sample :
- Le - 19 = 16
- Le - 17 = 22
- Le - 15 = 12
Total number of sample = 50
The percentage natural abundance of the isotopes can be calculated :
Number of each isotope ÷ total number of sample
Percentage abundance of Le isotopes
- Le - 19 =

- Le - 17 =

- Le - 15 =

Therefore, the percentage abundance of Le - 19, Le - 17 and Le - 15 isotopes are 0.32, 0.44 and 0.24 respectively.
Learn more : brainly.com/question/16078327
PO4 anion has a 3- charge.A sodium cation , has a 1+ charge.Now , you have to think how many Na ions you need to fully neutralize the PO4 's 3- charge. Answer 3. That's because a molecule must have a neutral charge (a 0 charge). 3+(-3)=0.So , sodium phosphate has the formula Na3PO4.
Answer:
18,1 mL of a 0,304M HCl solution.
Explanation:
The neutralization reaction of Ba(OH)₂ with HCl is:
2 HCl + Ba(OH)₂ → BaCl₂ + 2 H₂O
The moles of 17,1 mL≡0,0171L of a 0,161M Ba(OH)₂ solution are:
= 2,7531x10⁻³moles of Ba(OH)₂
By the neutralization reaction you can see that 2 moles of HCl reacts with 1 mole of Ba(OH)₂. For a complete reaction of 2,7531x10⁻³moles of Ba(OH)₂ you need:
= 5,5062x10⁻³moles of HCl.
The volume of a 0,304M HCl solution for a complete neutralization is:
= 0,0181L≡18,1mL
I hope it helps!