Chloroplasts are only found in plant cells because it is the organelle that makes photosynthesis possible and it makes food for the plant cells as in it makes its own food and animal cells dont need them because animals eat other animals for that food
The substance must be able to alter its physical characteristic (for example, its color) in accordance to a change in pH. One example of this is litmus paper, which becomes red under acidic conditions and blue under basic conditions.
The correct answer is iron.
The scientists from Britain discovered a soap with magnetic characteristics that could exhibit huge applications in the manner to fight against the damaging oil spills. In the mentioned soaps, the iron-abundant salts are supplemented to establish metallic centers inside the particles of the soap.
After the solution is treated in a water source, a magnet was utilized to subjugate both the surface tension and gravity of the water, levitating the iron-rich scrubbing bubbles so that they can be withdrawn easily.