<span>When two hydrogen atoms approach each other to form a chemical bond, both attractive and repulsive forces are present. This is due to the negative and positive charges within the atoms. The electrons of each of the hydrogen atoms repel each other, while the nuclei also repel each other. At the same time, the electron and nucleus of both hydrogen atoms attract each other. So the answers are:
</span><span>2. when to atoms of H approach each other,the two nuclei repel each other
3. when to atoms of H approach each other, each electron is attracted by the other nucleus </span>
Answer:
The equilibrium shifts to the left, and the concentration of Ba2+(aq) decreases
Explanation:
Whenever a solution of an ionic substance comes into contact with another ionic compound with which it shares a common ion, the solubility of the ionic substance in solution decreases significantly.
In this case, both BaSO4 and Na2SO4 both possess the SO4^2- anion. Hence SO4^2- anion is the common ion. Given the equilibrium;
BaSO4(s) <—> Ba2+ (aq) + SO4 2- (aq), addition of Na2SO4 will decrease the solubility of BaSO4 due to the presence of a common SO4^2- anion compared to pure water.
This implies that the equilibrium will shift to the left, (more undissoctiated BaSO4) hence decreasing the Ba^2+(aq) concentration.
Answer:
2NO(g) + O2(g) --> 2NO2(g)
now 400 ml of NO × 2 mol of NO2/2 mol of NO
= 400 ml of NO2
now 500 ml of O2 × 2 mol of NO2/1 mol of O2
= 1000 ml of NO2
now 400 ml of NO2 × 1 mol of O2/2 mol of NO
= 200 ml
subtract that from 500 ml of total i.e. 500-200 =300 ml
The total volume of the reaction mixture is 1000 ml -300ml = 700 ml
Answer:
<em>A not reasonable explanation for an aerospace engineer designs a rocket to have three stages is</em>:
- <u><em>A. To simplify the design of the rocket</em></u>
Explanation:
A <em>three stages rocket</em> permits to separate the fuel compartments. The rocket must be launched with a huge amount of fuel to last the entire travel. Then the initial mass of the rocket and the fuel is considerably large.
As the rocket flies, part of the fuel is consumed and so some compartements may be separated and removed decreasing the mass of the rocket as it flies (<em>option D. </em>is a reasonable explanation), so the rocket only carries the necessary mass (<em>statement B</em>. is a reasonable explanation).
As the rocket moves away from Earth, the gravitational force decreases and, in the space, the amount of thrust needed is lesser, which the aerospace engineers take into account for the design (choice C. is a reasonable explanation).
The only <em>not reasonable explanation to design a three stage rocket</em> is to <em>simplify the design of the rocket</em>: designing a rocket with three modules each with different features, functions, and the detachment mechanisms brings lot of complex problems to solve. So, o<em>ption A. </em>is the correct answer.
