<span>
</span>

<span>
You have OH- conc = </span>2.3 ✕ 10−6 m
From the formula, you can observe the ratio of Cu2+ to OH- is 4 : 6 = 2:3
So, for 2.3 ✕ 10−6 m OH-
[Cu2+] =

.
Oxygen-16 is the atom in question.
- Atomic number: 8.
- Mass number: 16.
<h3>Explanation</h3>
The superscript of the ion says "2-". That means that the ion here carries a charge of -2.
- The charge is negative, meaning that there are more electrons (which are negative) than protons (which are positive) in that ion.
- The size of the charge is 2. There are two more electrons than protons in that ion.
There are 10 electrons in total in that ion. There are two more electrons than protons. That means that there are 10 - 2 = 8 protons in that ion.
The atomic number of an atom is the same as its number of protons. The atomic number of X is 8.
The atomic number determines the element. Atomic number 8 is oxygen. Thus element X is oxygen.
Mass number is the sum of number of protons and neutrons in an atom. 8 + 8 = 16 for this atom.
<h2>Natural Abundance for 10B is 19.60%</h2>
Explanation:
- The natural isotopic abundance of 10B is 19.60%.
- The natural isotopic abundance of 11B is 80.40%.
- The isotopic masses of boron are 10.0129 u and 11.009 u respectively.
For calculation of abundance of both the isotopes -
Supposing it was 50/50, the average mass would be 10.5, so to increase the mass we need a more percentage of 11.
Determining it as an equation -
10x + 11y= 10.8
x+y=1 (ratio)
10x + 10y = 10
By taking the denominator away from the numerator
we get;
y = 0.8
x + y = 1
∴ x = 0.2
To get percentages we need to multiply it by 100
So, the calculated abundance is 80% for 11 B and 20% 10 B.
Out of the following given choice:
A. The increase in
the airspace occupied by vinegar molecules
B. The chemical reaction with nerves, which is slower than
other sensory processes
C. Attractive forces between the air and vinegar molecules
D. Random collisions between the air and vinegar molecules.
<span>The answer is
D. While the particles may be
moving at high velocities even at room
temperatures, the delay is due to the numerous collisions
between the vinegar molecules and the air molecules.This changes the vinegar’s
molecules directions from straight lines to random unpredictable paths</span>