I'm pretty sure the answer is 1. I and III
Answer:
The third option "A molecule of a compound is composed of at least two types of atoms" is correct
Explanation:
This question isn't about molecules, it's about elements and compounds.
Elements are made of one and only one type of atoms, while compounds are made of more than one type of atoms.
(Molecules are just groups of atoms, it doesn't matter what they're made of)
Answer:
The answer to your question is d.
Explanation:
Chemical changes happen when the substance changes its original properties to form a new one. So option 1 is incorrect.
Dissolving a new substance does not form new substances as I mentioned before. The second option is incorrect.
The third option is also wrong because dissolving a substance does not separate anything.
The fourth option is correct, dissolving a substance allows us to make solutions.
