The answer is A because An Indicator" changes color when it comes in contact with an acid or a base
An indicator could be anything like:
1) Litmus paper
2) Bromothymol blue
3) Phenolphthalein
Heat
gained in a system can be calculated by multiplying the given mass to the
specific heat capacity of the substance and the temperature difference. It is
expressed as follows:<span>
Heat = mC(T2-T1)
345.2 = 89.5(C)(305 - 285)
C = 0.1928 </span>J/g•K
Thermal energy is the force of the kinetic and potential energies of all particles in an object
When we swim we apply force and push the water backward with the help of our hands. In response, The water pushes us forward with an equal force. Thus, in order to move forward and swim, the swimmer lushes the water backward. Newton's 3rd law of motion