(Question)
Q: Limestone is insoluble in water, so what can dissolve it? Choices: - calcium - dioxide - oxygen - acid A:
(Answer)
acid

(Question)
Q: Which type of electrons plays the most important role in chemical reactions? Choices: - noncovalent - intermediate - transition - valence A:
(Answer)
valence

(Question)
Q: What types of drugs affect the brain and influence how a person can feel, think, or act? Choices: - antibiotics - analgesics - prescription - psychoactive A:
(Answer)
psychoactive