Answer:
7.951 x 0²³atoms
Explanation:
Mass of Fe₃O₄ = 140g
Solution:
To find the number of oxygen atoms in iron(III) oxide, we first find the number of moles in the compound:
Number of moles = 
Molar mass of Fe₃O₄ = (3x56) + (4x64) = 168 + 256 =424g/mol
Number of moles = 
= 0.33mole
1 mole of an atom contains 6.02 x 10²³atoms
∴number of oxygen atoms in Fe₃O₄ = 4 x 0.33 x 6.02 x 10²³atoms
= 7.951 x 0²³atoms
If we compare a cell with an egg there is a major difference between the outer membrane
in case of cell they are bounded by semi permeable membrane
The semi permeable membrane is a selectively permeable membrane which allows the movement of only solvent molecule and not solute molecules through it.
So water can move into or out of the cell through cell membrane by a special physical process known as osmosis.
the water will move from a low concentration gradient to high concentration gradient.
The state of energy that is forbidden is 2p orbital. The correct option is b).
<h3>
What is the energy state of electrons?</h3>
The energy state of an electron depends upon the presence of the electron on the orbitals. Lower the energy they will be in the lower orbital. When they get higher energy they move to the higher orbital.
By using the Selection Rules for Electron Transitions
1.) ?l = +/- 1 and
2.) ?m = 0, +/- 1
The conservation of angular momentum is required by these laws. A photon's inherent angular momentum is 1. As 4p is higher than 2p and the electron is lowering its energy. So, it will go down to 2p orbital.
Thus, the correct option is b). 2p orbital.
The question is incomplete. Your full question is given below:
a) 3d
b) 2p
c) 1s
d) 2s
To learn more about the energy state of electrons, refer to the link:
brainly.com/question/4138621
#SPJ4
In a given solution, the concentration of hydrogen ions and hydroxide ions are related to each other by the following expression:
pH + pOH = 14
where, pH = - log[H+] and pOH = - log [OH-]
In this case, the concentration of sulfuric acid is given as 2.1 x 10^-4 M. Since each molecule of sulfuric acid (H2SO4) contains 2 atoms of hydrogen, the concentration of hydrogen ions in this solution is twice that of sulfuric acid. That is,
Concentration of H+ ions = 2 x 2.1 x 10^-4
= 4.2 x 10^-4 M
This means, pH = -log (4.2 x 10^-4) = 3.38
Since pH + pOH = 14
pOH = 14 - 3.38 = 10.62
This means, 10.62 = -log [OH-]
Solving the equation, we get [OH-] = 2.4 x 10^-11 M.
Hope this helps.
