Answer the following question given this paragraph: Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the world's most serious resource problem. How can that be? Water is almost everywhere. But much of it is unusable. What is usable is not always where it is needed. Q: What is the world's most serious resource problem? Choices: - gas shortage - citrus blight - deforestation - water scarcity A:
water scarcity
Answer the following question given this paragraph: Density describes how much matter is in a certain amount of space. Substances that have more matter packed into a given space have higher densities. The water in a drinking glass has the same density as the water in a bathtub or swimming pool. All substances have characteristic densities, which does not depend on how much of a substance you have. Q: What describes how much matter is in a certain amount of space? Choices: - volume - mass - viscosity - density A:
density
Q: Answer the following question given this paragraph: Light is produced when charged particles accelerate . As a result changing electric and magnetic fields radiate outward. The traveling electric and magnetic fields of an accelerating (often oscillating) charged particle are known as electromagnetic radiation or light. Q: Light is produced when charged particles do what, frequently in the form of oscillating? Choices: - decelerate - increase - offset - accelerate A:
A: accelerate
Question: Answer the following question given this paragraph: Electronegativities generally increase from left to right across a period. This is due to an increase in nuclear charge because of the greater number of protons in the nucleus. Alkali metals have the lowest electronegativities, while halogens have the highest. Because most noble gases do not form compounds, they are generally not assigned electronegativity values. Note that there is little variation among the transition metals. Electronegativities generally decrease from top to bottom within a group due to the larger atomic size. Q: Why do electronegativities decrease from top to bottom? Choices: - smaller atomic size - larger atomic variation - larger electric pull - larger atomic size A:
Answer: larger atomic size
*Question*
Answer the following question given this paragraph: Secondary pollutants form from primary pollutants. Many occur as part of photochemical smog . This type of smog is seen as a brown haze in the air. Photochemical smog forms when certain pollutants have a chemical reaction in the presence of sunlight. Photochemical smog consists mainly of ozone (O 3 ). Ozone near the ground is a pollutant ( Figure below ). This ozone is harmful to humans and other living things. However, ozone in the stratosphere protects Earth from the Sun's harmful ultraviolet radiation. Q: Photochemical smog consists mainly of what? Choices: - acid - oxygen - carbon - ozone A:
**Answer**
ozone
Q: Answer the following question given this paragraph: Chemical reactions either require energy or release energy. The amount of energy needed or released depends upon the structure of the molecules that are involved in the reaction. Some reactions need to be heated for long periods of time in order for change to take place. Other reactions release energy, allowing heat to be given off to the surroundings. Q: Chemical reactions either require or release what? Choices: - light - electricity - enzymes - energy A:
A: energy