Answer: The de broglie wavelength is
.
Explanation:
Calculate
as follows.

where,
h = plank's constant = 
p = momentum = 
Putting the values in the formula as follows.

=
= 
Thus, the de broglie wavelength is
.
Answer:
Momentum of first train car will reduce
Explanation:
When the moving care collides with the stationary car, it will increase the momentum of the stationary car. However, its own momentum will reduce.
It is so because the speed of the first train car will reduce after collision due to loss of energy in the collision while the stationary car may gain some momentum due to rise in velocity from zero (velocity at stationary position).
Answer:
The Correct increasing order of solubility is O2 < Br2 < LiCl < Methanol (CH3OH)
Explanation:
Solubility of compounds or molecules are solely dependent on its inter molecular forces or bonding present in them.
Molecules with Hydrogen bonding usually very soluble in water. Ionic compounds are also very soluble in water because they form ions in solutions. Molecules that possess van der waal forces are usually insoluble in water because they are non-polar.
- O2 (oxygen gas) and Br2 (bromine gas) have van der waal forces in them. Van der waal forces are stronger in Br2 (bromine gas) than O2 (oxygen gas) because Br2 has more number of electrons.
- LiCl is ionic in nature which makes it dissolve in water readily. it easily forms its ions (Li+ and Cl- ) in solutions.
- Methanol (CH3OH) has the highest solubility in water compared to LiCl, Br2 and O2 because it contains Hydrogen bonding which is strongest of all inter molecular forces.