Hydrogen bonds between adenine & thymine or guanine and cytosine form that join the two strands of the dna double helix. what is the blank? (hint: the third letter of the first word is an s & both words combined can only be 9 letters) ! i have no idea : (

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)

How are isotopes of the same element alike?