Q: Cigarettes are a major source of what kind of chemical substances linked with cancer? Choices: - chemicals - pesticides - alkaloids - carcinogens A:
carcinogens

Q: What rises through solid rocks where conditions are right? Choices: - crystals - water - nitrogen - magma A:
magma

Q: Q: Exposure to what can increase the amount of pigment in the skin and make it appear darker? Choices: - gamma rays - sunlight - nuclear radiation - ultraviolet radiation A:
A: ultraviolet radiation

Question: Q: What important aspect of the scientific method is a suggested explanation for an event, which can be tested? Choices: - scientific control - string theory - independent variable - hypothesis A:
Answer: hypothesis

*Question*
Q: People with red hair usually have what type of skin? Choices: - dark - oily - dry - light A:
**Answer**
light

Q: Q: Elements with magic numbers of what tend to have more stable isotopes? Choices: - nucleus - pressure - molecules - protons A:
A: protons