Answer:
0.5 × 10²³ atoms of iodine
Explanation:
Given data:
Mass of calcium iodide = 12.75 g
Number of atoms of iodine = ?
Solution:
First of all we will calculate the number of moles of calcium iodide.
Number of moles = mass/ molar mass
Number of moles = 12.75 g/ 293.9 g/mol
Number of moles = 0.04 mol
In one mole of calcium iodide there are two moles of iodine.
Thus in 0.04 moles:
0.04 mol × 2 = 0.08 moles of iodine
Now we will use the Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
0.08 moles of iodine × 6.022 × 10²³ atoms / 1 mol
0.5 × 10²³ atoms of iodine.
<span>The answer is: more protons than neutrons
The stability of the nucleus is based on the ratio of neutrons and protons present in the nucleus. if the number of protons is equal to the number neutrons then the nucleus
is stable but in case the number of protons is more than the number neutrons or the other way round the nucleus to gain stability starts interconversion of neutron to proton
or electron or decreases proton numbers. In case of nucleus containing high energy, the nucleus releases it. Such nuclei which release energy to gain stability are called
radioactive nuclei and the phenomenon is called radioactivity.</span>
<span>Rules for the Principal Energy Level. A principal energy level may contain up to 2n2 electrons, with n being the number of each level. The set of three p orbitals can hold up to 6 electrons. Thus, the second principal energy level can hold up to 8 electrons, 2 in the s orbital and 6 in the p orbital.</span>
Answer: The concentrations of A , B , and C at equilibrium are 0.1583 M, 0.2583 M, and 0.1417 M.
Explanation:
The reaction equation is as follows.

Initial : 0.3 0.4 0
Change: -x -x x
Equilbm: (0.3 - x) (0.4 - x) x
We know that, relation between standard free energy and equilibrium constant is as follows.

Putting the given values into the above formula as follows.


x = 0.1417
Hence, at equilibrium
= 0.1583 M
= 0.2583 M