Answer:
The correct answer is option b.
Explanation:

The ionic product of water : 
![K_w=[H^+][OH^-]](https://tex.z-dn.net/?f=K_w%3D%5BH%5E%2B%5D%5BOH%5E-%5D)
A pure water has equal concentration of hydrogen ions and hydroxide ions, hence neutral.
![K_w=[H^+][H^+]=[H^+]^2](https://tex.z-dn.net/?f=K_w%3D%5BH%5E%2B%5D%5BH%5E%2B%5D%3D%5BH%5E%2B%5D%5E2)
The ionic product of water at 283 K = 
![K_w=[H^+]^2](https://tex.z-dn.net/?f=K_w%3D%5BH%5E%2B%5D%5E2)
![0.29\times 10^{-14}=[H^+]^2](https://tex.z-dn.net/?f=0.29%5Ctimes%2010%5E%7B-14%7D%3D%5BH%5E%2B%5D%5E2)
![[H^+]=5.385\times 10^{-8} M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D5.385%5Ctimes%2010%5E%7B-8%7D%20M)
The pH of the water at 283 k;
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
![=-\log[5.385\times 10^{-8} M]=7.26](https://tex.z-dn.net/?f=%3D-%5Clog%5B5.385%5Ctimes%2010%5E%7B-8%7D%20M%5D%3D7.26)
A pure water has equal concentration of hydrogen ions and hydroxide ions,So water will e neutral at this temperature also.
The correct answer is option b.
Yes they libed before the dinasours and during the jurassic (triassic period).
Bohr's model explained the position of the electron, proton, and neutron in the atom of the element. The energy at the n = 2 level of the atom will be - 3.40 eV.
<h3>What is the principal quantum number (n)?</h3>
The principal quantum number (n) has been the distance of the electron of that atom in the nucleus and its energy in the structure. It can also be said to define the size of the atomic orbit.
n = 2 is the first excited state whose energy is calculated as:
Eₙ = − 13.6 ÷ n² eV
E₂ = - 13.6 eV ÷ 2²
= -3.40 eV
Therefore, -3.40 eV is the energy of electron at n = 2.
Learn more about principal quantum numbers here:
brainly.com/question/14307071
#SPJ4
Answer: False
Explanation:
An acid is defined as the substance which looses hydrogen ion or hydronium ions when dissolved in water.
A base is defined as the substance which looses hydroxide ions when dissolved in water.
If the solution has higher hydronium ion concentration as compared to the hydroxide ion concentration, then the pH will be low and the solution will be acidic.
If the solution has low hydronium ion concentration as compared to the hydroxide ion concentration then the pH will be high and the solution will be basic.
A is the answer, and put the choices