(a) We can find the current flowing between the walls by using Ohm's law:

where

is the potential difference and

is the resistance. Substituting these values, we get

(b) The total charge flowing between the walls is the product between the current and the time interval:

The problem says

, so the total charge is

The current consists of Na+ ions, each of them having a charge of

. To find the number of ions flowing, we can simply divide the total charge by the charge of a single ion:
Answer:
The appropriate response will be "Length must be increased by 0.012%".
Explanation:
The given values is:
ΔT = 5 s/day
Now,
⇒ 
On multiplying both sides by "100", we get
⇒ 
⇒
(%)
∵ 
On substituting the values, we get
⇒
% =
%
On applying cross multiplication, we get
⇒
% =
%
⇒ = 
⇒ = 
⇒ =
%
Answer:

Explanation:
We need to find the energy for an electron to jump from n = 1 to n = 4.
The energy in transition from 1 state to another is given by :

The difference in energy for n = 1 to n = 4 is:

So, the required energy is equal to
.
Answer:
A & D
Explanation:
A single-displacement reaction is a chemical reaction whereby one element is substituted for another one in a compound and thereby generating a new element and also a new compound as products.
From the options, only options A & D fits this definition of single-displacement reactions.
For option D: Both left and hand and right hand sides each have one element and one compound. We can see that K is substituted from KBr to join Cl to form KCl and Br2 on the right hand side.
For option A: Both left and hand and right hand sides each have one element and one compound. We can see that OH is substituted from 2H2O to join Mg to form Mg(OH)2 and H2 on the right hand side.
The other options are not correct because they don't involve only and element and a compound on each side of the reaction.
Answer:
The inner planets are smaller and rockier
Explanation:
Astronomers divide the planets into two groups in Solar system, the inner planets and outer planets. The inner planets are smaller and rockier and it is closer to the sun. The outer planets are larger , further far away and made of gas
The inner planets are Mercury, Venus , Earth and Mars. The outer planets Jupiter , Saturn , Uranus and Neptune comes after an asteroid belt. In some other planetary systems the gas are close to the sun.
particles in a disk of gas and dust will form Planets. If they orbit the star they are colliding and sticking. The stars wind blows away their gases . So the nearest planets to starts are rockier.