A group of students experimented
about SUBSTANCE X. The following
were their observations When
Substance X was heated, it decomposed
into a new solid substance labeled as
Substance Y and a gas labeled as
Substance Z Further heating of
substances Y and Z yielded no new
product.

9. Which of the substances is/are
compound/s?
A. Substance X
B. Substance Y
C. Substance Z
D. Substances Y and Z

10. Which of the substances is/are
element/s?
A. Substance X
B. Substance Y
C. Substance Z
D. Substances Y and Z​