Answer is: lithium is the least reactive and potassium is the most reactive of the three alkali elements.
<span>The </span>reactivity<span> of the alkali metals increases down the group because one valence electron (I group of Periodic system of elements) is farther away from nucleus and attraction force between electron and proton is weaker.</span>
Answer:
Both B and D are correct.
Explanation:
B + H₂O ⇌ BH⁺ + OH⁻
If you add more products, the position of equilibrium will shift to the left to decrease their concentrations (Le Châtelier's Principle). The concentration of reactants will increase, but the equilibrium concentrations of products will also be higher than they were initially.
A is wrong. The equilibrium constant is a constant. It does not change when you change concentrations.
C is wrong. Per Le Châtelier's Principle, the concentrations must change when you ad a stress to a system at equilibrium.
(This is a poorly-worded question. "They" are probably expecting answer D.)
Over here you have to use the formula: <span>P1/T1= P2/T2
P1= 7.58
T1= 639
P2= ?
T2= 311
</span><span>7.58/639 = ?/311
</span>= 3.689 kPa
Answer:
Solution Y is more acidic
Explanation:
The pH value is an indicator of the concentration of hydrogen ions (H⁺) in an aqueous solution, and it is defined as:
pH= -log [H⁺]
⇒ ![[H^{+} ]= 10^{-pH}](https://tex.z-dn.net/?f=%5BH%5E%7B%2B%7D%20%5D%3D%2010%5E%7B-pH%7D)
Where [H⁺] is the concentration of H⁺. A solution with a higher concentration of H⁺ is more acidic, and a solution with a lower concentration of H⁺ is less acidic or basic.
As result, <em>the lower the pH, the more the concentration of hydrogen ions ([H⁺]), and the aqueous solution is more acidic</em>.
Solution Y has a lower pH value (7.5) than solution X (9.4). So, solution Y is more acidic.
Answer:
The deuterium-tritium (DT, Figure 2) reaction is the most useful for fusion energy because it most easily overcomes the Coulomb repulsion, and it has the highest energy release among laboratory-feasible reactions.
Explanation:
When a deuterium nucleus (2H) and a tritium nucleus (3H) combine, the result is a helium nucleus and a very energetic neutron. Under the right circumstances, the energy released is sufficient to induce further fusion reactions.
