Answer:
C. transition elements
Explanation:
Transition elements are groups of metallic elements that have partially filled d orbitals. They occupy the d-block of the periodic table (Group 3-12). Examples of elements that fall under this category are Nickel (Ni), Cobalt (Co), Copper (Cu), Zinc (Zn) etc. Transition metals have outstanding properties that distinguishes them from other elements.
One of these properties is their ability to form colored compounds due to their unfilled d electron shells. They form ions that are usually colored in solid compounds and in solution.
Option (B) is the right answer.
Hydronium ion (
) concentration decreases by the <u>factor of 100</u>, if the pH of a solution increases from 2.0 to 4.0.
<h3>What is pH?</h3>
The hydrogen ion concentration in water is expressed by pH. Specific to aqueous solutions, pH is the <u>negative logarithm</u> of the hydrogen ion (H+) concentration (mol/L) : ![pH = -log_{10}[H_{3}O^{+} ]](https://tex.z-dn.net/?f=pH%20%3D%20-log_%7B10%7D%5BH_%7B3%7DO%5E%7B%2B%7D%20%20%5D)
Acidic solutions are those with a pH under 7, and basic solutions are those with a pH over 7. At this temperature, solutions with a pH of 7 are neutral (e.g.<u> pure water</u>). The pH neutrality <u>relies on temperature, falling below 7 if the temperature rises above 25 °C</u>.
<h3>Given: </h3>
pH1( initial pH) = 2.0
pH2( initial pH) = 4.0
[H3O+] = initial hydronium concentration
[H3O+]* = final hydronium concentration
<h3>Formula used : </h3>
![pH = -log_{10}[H_{3}O^{+}]](https://tex.z-dn.net/?f=pH%20%3D%20-log_%7B10%7D%5BH_%7B3%7DO%5E%7B%2B%7D%5D)
<h3>Solution: </h3>
![pH = - log_{10}[H_{3}O^{+}] \\\\= > 10^{-pH} = [H_{3}O^{+}] \\\\similarly, \\\\10^{-pH} = [H_{3}O^{+}]*\\\\ = > 10^{-4} = [H_{3}O^{+}]*\\\\Now, \frac{[H_{3}O^{+}]*}{[H_{3}O^{+}]} = 10^{-2}](https://tex.z-dn.net/?f=pH%20%3D%20-%20log_%7B10%7D%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%5C%5C%5C%5C%3D%20%3E%2010%5E%7B-pH%7D%20%3D%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%5C%5C%5C%5Csimilarly%2C%20%5C%5C%5C%5C10%5E%7B-pH%7D%20%3D%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%2A%5C%5C%5C%5C%20%3D%20%3E%2010%5E%7B-4%7D%20%3D%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%2A%5C%5C%5C%5CNow%2C%20%5Cfrac%7B%5BH_%7B3%7DO%5E%7B%2B%7D%5D%2A%7D%7B%5BH_%7B3%7DO%5E%7B%2B%7D%5D%7D%20%20%3D%2010%5E%7B-2%7D)
Thus , the concentration of hydronium ion decreases by 100.
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The identity of the metal is copper.
<h3>What is specific heat?</h3>
The amount of energy needed to raise the temperature of one gram of a substance by one degree Celsius.
Using the formula of specific heat
H = mcdT
Where, H = Heat absorbed
m = mass of the metal
c = specific heat capacity of the metal
dT = temperature change
Putting the values in the equation
20 J = 0.0052 Kg × c × ( 40.0°C - 30.0°C)
c = 20 J/0.0052 Kg × ( 40.0°C - 30.0°C)
c = 385 JKg-1°C-1
Thus, the metal is copper.
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Explanation:
It's a distance-time graph showing the speed of an object
