Many extrusive volcanic rocks contain holes which have formed from

Answer    "a salt" would be the best answerexplanationsalts can be defined as ionic compounds that are neither acids nor bases. nacl is an example of a salt, and its ionic.an enzyme is an organic compound which is covalently bonded, not ionically bonded.acids are generally held together by covalent bondsan element does not need any bonds to exist

B.1 - hydrogren-1 can only mean there is 1 neutron. it's obvious there is 1 proton or else it wouldn't be hydrogen, so they wouldn't put a number after it unless they were indicating the number of neutrons