Hmmm.. i think B. I dont understand the the answer choices.
Answer:
In the given case, the atomic number of the given atom is 15, hence its nucleus contains 15 protons. The number of protons and electrons are the same in atom and that is what keeps it neutral. In the second case, the atomic number is 20. Hence, the atom will contain a total of 20 protons in its nucleus.
Explanation:
Answer:
28.58 g of NaOH
Explanation:
The question is incomplete. The missing part is:
<em>"Calculate the mass of sodium hydroxide that the chemist must weigh out in the second step"</em>
To do this, we need to know how much of the base we have to weight to prepare this solution.
First we know that is a sodium hydroxide aqueous solution so, this will dissociate in the ions:
NaOH -------> Na⁺ + OH⁻
As NaOH is a strong base, it will dissociate completely in solution, so, starting with the pH we need to calculate the concentration of OH⁻.
This can be done with the following expression:
14 = pH + pOH
and pOH = -log[OH⁻]
So all we have to do is solve for pOH and then, [OH⁻]. To get the pOH:
pOH = 14 - 13.9 = 0.10
[OH⁻] = 10⁽⁻⁰°¹⁰⁾
[OH⁻] = 0.794 M
Now that we have the concentration, let's calculate the moles that needs to be in the 900 mL:
n = M * V
n = 0.794 * 0.9
n = 0.7146 moles
Finally, to get the mass that need to be weighted, we need to molecular mass of NaOH which is 39.997 g/mol so the mass:
m = 39.997 * 0.7146
<h2>
m = 28.58 g</h2>
Answer:
The electronegativity differences between carbon and oxygen are not very large.
Explanation:
Between the atoms of carbon monoxide exists a covalent bond which attaches the carbon to the oxygen.
In this type of bonding, both atoms shares a given number of valence electrons to attain chemical stability.
A substance is polar when there is a distinct charge separation between the species.
For covalent bonds, the electronegativity difference plays in important role in determining the polarity of the compound. When the difference is large, the compound will be polar but when the difference is very small or zero, no polarity will exist.
In between carbon and oxygen of carbon monoxide, the electronegativity difference is very low.
Answer: The earth's atmosphere gets thinner with the increase in altitude. The earth's atmospheric layers are Troposphere, Stratosphere, Mesosphere, Ionosphere .
Explanation:
Good luck!
