Question
Which row identifies a chemical change and a physical change?
Answer/Explanation
Ans:
B
Question
When sulfur is heated it undergoes a ……1…… change as it melts.
Further heating causes the sulfur to undergo a ……2…… change and form sulfur dioxide.
Which words complete gaps 1 and 2?
Answer/Explanation
Ans: C
Question
X is a pink solid.
Y is a blue solid.
When X is heated, water is produced and the solid turns blue.
When water is added to Y, the solid turns pink.
What are X and Y?
Answer/Explanation
Ans: B
Question
Which change in reaction conditions increases both the collision rate and the proportion of molecules with sufficient energy to react?
A. addition of a catalyst
B. increasing the concentration of a reactant
C. increasing the surface area of a reactant
D. increasing the temperature of the reaction
Answer/Explanation
Ans:
D