Always remember that in organic molecules, carbon is always tetravalent (forms 4 bonds).

You can find detailed step-by-step breakdowns for these specific textbook versions on educational platforms like Gdz.ru or Reshak.ru.

This exercise appears at the end of (or similar introductory chapters on structure) in the 10th-grade Organic Chemistry textbook by G.E. Rudzitis and F.G. Feldman.

To understand the bonding, look at the ground state vs. the excited state: 1s22s22p21 s squared 2 s squared 2 p squared (2 unpaired electrons). Excited State ( C*cap C raised to the * power ): 1s22s12p31 s squared 2 s to the first power 2 p cubed (4 unpaired electrons).