Answer:
...BY CHOOSING A PROPER INDICATOR, SCIENTISTS CAN MINIMIZE THE DIFFERENCE IN THESE TWO NUMBERS,...
Explanation:
A chemical indicator is an agent or substance which gives a visible sign especially a color change when introduced to a solution of base indicating the threshold of the concentration of acid used in the titration procedure. These indicators include methyl orange, methyl red, phenolpthalein. They give a color change when the concentration of an acid as reached a critical limit in order for the reaction to be stopped. These indicators are involved in acid-base titrations, oxidation- reduction reactions and so on. More accurate results of the volume of the required acid or base is obtained by the introduction of these indicators.
<h3>Answer:</h3>
Strontium (Sr)
<h3>Explanation:</h3>
The condition given in statement is the presence of two valence electron. Hence, first we found the electronic configuration of given atoms as follow;
Rubidium [Kr] 5s¹
Strontium [Kr] 5s²
Zirconium [Kr] 4d² 5s²
Silver [Kr] 4d¹⁰ 5s¹
From above configurations it is cleared that only Strontium and Zirconium has two electrons in its valence shell.
We also know that s-block elements are more reactive than transition elements due to less shielding effect in transition elements hence, making it difficult for transition metals to loose electrons as compared to s-block elements. Therefore, we can conclude that Strontium present in s-block with two valence electrons is the correct answer.
Noble gases are the least reactive of all elements. That's because they have eight valence electrons, which fill their outer energy level. This is the most stable arrangement of electrons, so noble gases rarely react with other elements and form compounds.
The answer is 172.39950000000002
