D. a and b because same-charged particles repel each other
Answer: 
Explanation:Bond energy of H-H is 436.4 kJ/mole
Bond energy of C-H is 414 kJ/mol
Bond energy of C=C is 620 kJ/mol
Bond energy of C≡C is 835 kJ/mol

= {1B.E(C≡C)+2B.E(C-H) +1B.E(H-H)} - {1B.E(C=C)+4B.E(C-H)}


Answer:
c
Explanation:
when the river is affected by the acid rain many species go into extinction
Yes, Sharpies contain volatile solvents—and when inhaled these solvents can produce a "high." The effects of inhalants (including Sharpies) can be similar to those of alcohol and include slurred speech, lack of coordination, euphoria, and dizziness.