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.
Explanation:
Reaction equation:
CO + 2H₂ → CH₃OH
All the species are in gaseous state and the equation is balanced.
Change in pressure only affects equilibrium involving a gas or gases.
Based on Le Chatelier's principle, an increase in pressure will shift the position of equilibrium to the side having smaller volume or number of moles and vice versa.
CO + 2H₂ → CH₃OH
3moles of gases 1 mole of gas
An increase in pressure favors the forward reaction. A decrease in pressure will favor the backward step.
Answer:
Chemoautotrophs
Explanation:
Autotrophs are groups of organisms that are capable of manufacturing their own food (organic molecules) through the fixation of carbon dioxide. There are two types of autotrophs:
- <em>Photoautotrophs fix carbon dioxide by using light as the energy for driving the process.</em>
- <em> </em><em>Chemoautotrophs f</em><em>ix carbon dioxide by using energy from the oxidation of inorganic molecules such as magnesium, or sulfur.</em>
Chemoautotrophs usually inhabit extreme environment such hot vents, deep sea, etc.
Answer:
1) D; 2) B
Explanation:
1) <em>Conservation of atoms
</em>
D is correct.
It has four atoms of H and two of O on each side of the reaction arrow.
A. <em>Wrong</em>. It has the same number of H and O on each side, but it has the <em>wrong product</em>. The reaction forms O₂ molecules, not O atoms.
B. <em>Wrong</em>. Atoms are balanced, but the <em>products are incorrect</em>.
C. <em>Wrong</em>. Atoms are balanced, but the <em>reactants are incorrect</em>.
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2) <em>Chemical equations
</em>
B is correct.
The atoms are balanced, and the equation shows the correct formulas of the molecules.
A. <em>Wrong</em>. Atoms are balanced, and the formulas are correct, but the equation is <em>not in its simplest form</em>. The coefficients are not in their lowest terms. We must divide every coefficient by six to get the correct equation: H₂ + Cl₂ ⟶ 2HCl.
C. <em>Wrong</em>. The <em>reactants are incorrect</em>, and the equation is <em>not in its lowest terms</em>.
D. <em>Wrong</em>. The <em>reactants are incorrect</em>.
Answer:
1.08 g/L is the density of air.
Explanation:
Pressure of the gas = P (atm)
Volume of the gas = V (L)
Moles of gas = n = 
Temperature of the gas = T (K)
where:
D = density of the gas = 
R = universal gas constant
w = Mass of the gas
M =Molar mass of the gas
Given = P = 1.0 atm , T = 54°C = 327.15 K
Average molar mass of the gas = 29 g/mol
Putting all the given values in above equation.
D = 1.08 g/L
1.08 g/L is the density of air.
