Rashi D.

a) A balanced chemical equation always obeys law of conservation of mass. According to this law the mass of products must be equal to the mass of reactants. A reaction is said to be balanced when the total mass of atoms on both sides of the chemical reaction is equal.

b) The balanced equation is 2Na + 2H2O → NaOH + H2. Balance is necessary for every chemical equation.

The process of photosynthesis is commonly written as: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂. This means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products. 

Significance- It ensures that all living species have access to oxygen in the atmosphere. It keeps the ecosystem's oxygen and carbon dioxide levels in check. Plants are the source of fossil fuels. Energy is locked in fuel as a result of photosynthesis in the sun.

Cognitive development is the construction of thought processes, including remembering, problem solving, and decision-making, from childhood through adolescence to adulthoodCognitive development is the construction of thought processes, including remembering, problem solving, and decision-making, from childhood through adolescence to adulthood.