Answer:
For number 2, your answer is C.
Explanation:
The nucleus is positively charged because the proton is positive and a neutron is neutral. An electron has a negative charge.
Here we have to choose the challenge which is faced by the scientist to make a hydrogen fuel cell by using water.
The challenge that the scientists are facing a. decomposition of water requires a high energy.
For the generation of fuel cells by hydrogen the use of water (H₂O) is a challenging task as the H-O bond in water is so strong and need high activation energy.
As per the mechanism of hydrogen fuel cell generation of H₂ is compulsory. Water remains in its solution as H₂O⇔H⁺ + OH⁻. The breaking of hydroxide ion (OH⁻) to form free hydrogen need a high energy, which cannot meet easily by any energy source.
The sun is always a renewable energy source as the energy of sun is infinitive.
The decomposition of water will only produce oxygen (O₂) and hydrogen (H₂) among which H₂ will be used in the fuel cell and O₂ is not at all harmful.
The excess O₂ is always good for the environment as it is the breathing source in the living system.
