1. Which of the following is a compound?   Sodium sulfide solution   Sodium   Sodium sulfide   Hint Half-n-half Clue   2. Copper sulfate can be further subdivided into simpler substances by chemical means only. Therefore, it is _______.   a mixture   an element   a compound   Half-n-half Clue   3. Which of the following is the smallest part of a compound, whose properties are the same as those of the compound?   Molecule   Atom   Element   Mixture   Half-n-half Clue   4. Oxygen cannot be further subdivided into simpler substances by any physical or chemical means. Therefore, it is _______.   a compound   an element   a mixture   Half-n-half Clue   5. H2 and Fe represent _______.   mixtures   compounds   elements   Half-n-half Clue   6. H2O and FeS represent _______.   compounds   elements   mixtures   Half-n-half Clue   7. Which of the following is a pure substance made up of two or more types of atoms or elements?   Mixture   Element   Compound   Half-n-half Clue