<u>Answer:</u>
<em>1. A NaCl solution with a concentration of 50g/100mL of water at 40°C:</em> The NaCl solution with a given concentration is saturated at this temperature .As the temperature increases the solution will more dissolves.
<em>2. A sugar solution with a concentration of 200g/100mL of water at 40°C: </em>The sugar solution with a given concentration is saturated at this temperature. As the temperature increases the solution will more dissolves.
<em>3. A sugar solution with a concentration of 240g/100mL of water at 40°C:</em> The sugar solution with a given concentration is saturated at given temperature.
Let the mass of 2500 kg car be
and it's velocity be
and the mass of 1500 kg car be
and it's velocity be
.
After the bumping the mass be M and it's velocity be V.
By law of conservation of momentum we have

2500 * 5 + 1500 * 1=4000 * V
V = 14000/4000 = 7/2 = 3.5 m/s
So the velocity of the two-car train = 3.5 m/s
Absorption occurs when <span>all of the energy from light waves is transferred to a medium! </span>
"Ionization energy" is the one among the following choices given in the question that <span>decreases with increasing atomic number in Group 2A. The correct option among all the options that are given in the question is the third option or option "C". I hope that the answer has helped you.</span>