To put it simply, ionic bonds form when one atom transfers an electron to another atom. The atom that gains an electron becomes a negative ion while the atom that loses an electron becomes a positive ion. Covalent bonds form when two atoms share electrons. A hydrogen bond is when you have a negatively charged O, N, or F atom in one molecule, a positively charged H atom latched on to an O, N or F atom in another molecule. An example of a hydrogen bond is water.
Answer:
Según el CERN, en los primeros instantes del Big Bang no había demasiado calor como para que se formen átomos, como el hidrógeno (el elemento más abundante del universo). En estos primeros instantes, mucho antes que se cumpla un segundo (10 a la menos 32), solo había quarks y fotones.
That would be B. Each tRNA is attached to a particular aminoacid.
tRNA is single stranded and has sequences of 3 nucleotides called anticodons.
