Rosenbergs executed. On this day in 1953, Julius and Ethel Rosenberg, who were convicted of conspiring to pass U.S. atomic secrets to the Soviets, are executed at Sing Sing Prison in Ossining, New York. Both refused to admit any wrongdoing and proclaimed their innocence right up to the time of their deaths, by the electric chair.
Bonds between linking nitrogenous bases of two DNA strands are Hydrogen bonds with 3 H-bonds connecting cytosine and guanine and 2 H-bonds connecting adenine and thymine, while the bonds between the stacking of DNA are kept in close contact via van der waals interactions.
The nitrogen bases are held together by hydrogen bonds: adenine and thymine form two hydrogen bonds; cytosine and guanine form three hydrogen bonds. An important thing to remember about the structure of the DNA helix is that as a result of anti-parallel pairing, the nitrogen base groups face the inside of the helix while the sugar and phosphate groups face outward.