The 28 is the sum of the protons and neutrons in the element silicon.
ALL silicon atoms have 14 protons in the nucleus, so we can turn this into an equation:
#protons + #neutrons = 28
14 + #neutrons = 28
#neutrons = 14
#protons = 14
Answer:
c. 1.5 mol
Explanation:
- Firstly, we need to calculate the no, of moles of 39.0 grams of calcium fluoride.
n = mass / molar mass = (39.0 g) / (78.07 g/mol) = 0.499 mol ≅ 0.5 mol.
- CaF₂ ionized in water as:
<em>CaF₂ → Ca⁺² + 2F⁻.</em>
Every 0.1 mole of CaF₂ is ionized to 3 ions (1 ion of Ca⁺² and 2 ions of F⁻).
<em>So, 0.5 mol of CaF₂ will contain (3 x 0.5 mol = 1.5 mol) of ions.</em>
Thus, the right choice is "c. 1.5 mol".
The correct answer would be: Atoms
I hope that this helps you!
Answer : The length of a one-dimensional box for an electron is 
Explanation :
The energy level of quantum particle in a one-dimensional box is given as:

where,
= 479 kJ/mol = 479000 J/mol
n = energy level = 1
h = Planck's constant = 
m = mass of electron = 
L = length of a one-dimensional box = ?
Now put all the given values in the above formula, we get:


conversion used : 

Therefore, the length of a one-dimensional box for an electron is 