Answer no 1)
The correct option is A) He did not try to learn it. It was natural.
As Sergei did not put any effort in learning the art of tongue rolling, hence we can assume that this characteristic was found to be naturally present in Sergei. This hence shows that Sergei has acquired the characteristic of tongue rolling through inheritance.
Answer No 2)
We can learn whether other persons in the class have the characteristic of tongue rolling or not by observing them. In the students who can roll their tongue we can conduct a survey asking them whether they tried to learn the trait or did not put any effort to learn tongue rolling. The students who learned the skill by practicing might have acquired the characteristic from learning.
Answer No 3)
We can survey the class for features like eye color, hair color, height, weight. We can ask certain questions in our survey like whether the characteristic can be seen in either the mother, father or other siblings.
Answer:
Explanation:
Combination of oxidation and reduction reactions.
Where there is oxidation, there is reduction too.
You are given
300 grams of FeCr2O7. You are required to get the mass of O2 in grams. The first
thing to do is to find a reaction between FeCr2O7 and O2. The balanced chemical
reaction is 2Fe + 6Cr + 21/2O2 -> Fe2(Cr2O7)3. The molar mass of Fe2(Cr2O7)3
is 759.65 grams per mole and 32 grams per mole for O2.
<span>
300g Fe2(Cr2O7)3
(1 mol Fe2(Cr2O7)3/759.65 g Fe2(Cr2O7)3)(21/2 mol O2/1 mole Fe2(Cr2O7)3)(32 g
O2/1 mole O2) = <u>132.7 g O2</u></span>
