9 Icse Solutions | Dr Viraf J Dalal Chemistry Class

She opened the book to a page on atomic structure. “See? You attempted Q.7 on calculating the number of electrons in Ca^2+ . You wrote 18. That’s correct. But you got confused on the reasoning. Look at the solution—it doesn’t just say ‘Answer: 18’. It breaks it down: Atomic number of Ca is 20. Neutral atom has 20 electrons. It loses 2 electrons to form Ca^2+ . So, 20 – 2 = 18.”

That night, he tackled Chapter 4: “Atomic Structure and Chemical Bonding.” He spent an hour trying to draw the electron dot diagram for Magnesium Chloride (MgCl₂) on his own. He drew magnesium with two dots, chlorine with seven, but he couldn’t figure out the transfer. He gave up, looked at Dr. Dalal’s solutions, and found a step-by-step breakdown: “Mg (2,8,2) has 2 valence electrons. It loses them to become Mg²⁺. Each Cl (2,8,7) gains 1 electron to become Cl⁻. Two chlorine atoms are needed.” dr viraf j dalal chemistry class 9 icse solutions

He decided to use it strategically. He made a rule: Attempt first, verify second, understand third. She opened the book to a page on atomic structure

The diagram suddenly made sense. It was like a detective revealing the clues to a mystery. You wrote 18

He wrote a small note on the inside cover of his solution book: “Not a crutch. A catalyst.”

Rohan didn’t panic. He heard Dr. Dalal’s voice in his head—not literally, but the logic of the solutions. He broke down the numerical step by step. He drew the electron dot diagrams with confidence. He wrote the reasoning for why sodium chloride conducts electricity in solution but not in solid state, using the precise keywords he had absorbed from the solution guide: “mobile ions vs. fixed lattice.”