Answer:Yes, water indeed expands when it changes form from liquid to solid. And this is because water has a property called “hydrogen bonds”, and these bonds occur between each water molecule. But when water is in a liquid form these hydrogen bonds break more easily and occur less frequently. When the temperature drops the kinetic energy also drops, which in turn makes hydrogen bonds form more frequently. So the water molecules form a lattice, which is less dense than regular liquid water.
Explanation:
The ratio of concentration of ionized acid to the initial concentration of acid multiplied by 100 will give the percent ionization of a weak acid in water increases as the concentration of acid decreases.
Explanation:
Percent ionization is used for quantifying the number of ions present in the weak acid when dissolved in a solution. So it is similar to the pKa value. The percent ionization value can be determined as negative log of dissociation constant. Also the as the number of ions increases in weak acid, the concentration of acid will be decreasing . It can be calculated using the formula for percent ionization as follows:

As the water volume or concentration increases, the acid will get diluted much more thus leading to decrease in the concentration of acid.
So the ratio of concentration of ionized acid to the initial concentration of acid multiplied by 100 will give the percent ionization of a weak acid in water increases as the concentration of acid decreases.
M = 30 g = 0.03 kg, the mass of the bullet
v = 500 m/s, the velocity of the bullet
By definition, the KE (kinetic energy) of the bullet is
KE = (1/2)*m*v²
= 0.5*(0.03 kg)*(500 m/s)² = 3750 J
Because the bullet comes to rest, the change in mechanical energy is 3750 J.
The work done by the wall to stop the bullet in 12 cm is
W = (1/2)*(F N)*(0.12 m) = 0.06F J
If energy losses in the form of heat or sound waves are ignored, then
W = KE.
That is,
0.06F = 3750
F = 62500 N = 62.5 kN
Answer:
(a) 3750 J
(b) 62.5 kN
Small evidence is also called trace evidence.