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.
Is this astronomy? If it is, Space Station
Answer:
A 2.8 liters
Explanation:
Step 1: Write the balanced equation
N₂ + 3 H₂ ⇄ 2 NH₃
Step 2: Establish the appropriate volume ratio
At the same temperature and pressure, the volume ratio of H₂ to NH₃ is 3:2.
Step 3: Calculate the volume of ammonia produced from 4.2 L of hydrogen
4.2 L H₂ × 2 L NH₃/3 L H₂ = 2.8 L
Strontium has an electron configuration of [Kr]5s²
<h3>Further explanation </h3>
In an atom there are levels of energy in the shell and sub shell
This energy level is expressed in the form of electron configurations.
Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d and f. The maximum number of electrons for each sub shell is
s: 2 electrons
p: 6 electrons
d: 10 electrons and
f: 14 electrons
From an electron configuration of [Kr]5s² can be concluded :
- element is in period 5 (5 = shell)
- element is group 2(valence electron =2 and block s)
- has atomic number 38 (Kr = 36 + 2(valence elektron from 5s²)
If we look at the periodic system, the elements that meet the requirements in question are Strontium (Sr)
Answer:
The mass of KClO₃ that will absorb the same heat as 5 g of KCl is 3.424 g
Explanation:
Here we have
Heat of solution of KClO₃ = + 41.38 kJ/mol.
Heat of solution of KCl (+17.24 kJ/mol)
Therefore, 1 mole of KCl absorbs +17.24 kJ during dissolution
Molar mass of KCl = 74.5513 g/mol
Molar mass of KClO₃ = 122.55 g/mol
74.5513 g of KCl absorbs +17.24 kJ during dissolution, therefore, 5 g will absorb
Therefore the amount of KClO₃ to be dissolved to absorb 1.156 kJ of energy is given by
122.55 g of KClO₃ absorbs + 41.38 kJ, therefore,
Therefore the mass of KClO₃ that will absorb the same heat as 5 g of KCl = 3.424 g.
