As Figure above shows, the distance between particles is much smaller for the solid and liquid states than for the gas state. In the solid state, particles are fixed in place, while particles are more free to move in the liquid and gas states. The particles in the solid and liquid states "stick together," but in the gas state, they move freely about the container. In general, it requires energy to separate individual particles. If we want to make a solid adopt a liquid form, we can add energy in the form of heat, increasing the temperature of the substance. Conversely, if we want to convert a substance from a gas to a liquid or from a liquid to a solid, we remove energy from the system and decrease the temperature. Pressure also plays an important role in changes of state, which will be discussed later on. We will study these difference in greater detail in the chapter States of Matter. John is studying the different states of matter. Today, he has a matter in three states in front of him, state A, state B, and state C. State A is in solid state. State B is in liquid state. And, state C is in gaseous state. He needs to determine the properties of each state. In which state the particles are less free, state A or state B?
Ans: state A

Sand mining is a direct cause of erosion, and impacts the local wildlife.[2] Various animals depend on sandy beaches for nesting clutches, and mining has led to the near extinction of gharials (a species of crocodile) in India. Disturbance of underwater and coastal sand causes turbidity in the water, which is harmful for organisms like coral that need sunlight. It can also destroy fisheries, financially harming their operators. Removal of physical coastal barriers, such as dunes, sometimes leads to flooding of beachside communities, and the destruction of picturesque beaches causes tourism to dissipate. Sand mining is regulated by law in many places, but is often done illegally.[3] Globally, it is a $70 billion industry, with sand selling at up to $90 per cubic yard.[4] Two coastal Canadian towns, Hammond and Soundville decided to start sand mining to bring more money to their budgets. A few months later however, Hammond decided to stop all mining operations and find other sources of income. they wanted to protect the environment. Which village harmed fewer fisheries?
Ans: Hammond

Another major cause of extinction is global warming , which is also known as global climate change. During the past century, the Earth's average temperature has risen by almost 1C (about 1.3F). You may not think that is significant, but to organisms that live in the wild and are constantly adapting to their environments, any climate change can be hazardous. Recall that burning fossil fuels releases gasses into the atmosphere that warm the Earth. Our increased use of fossil fuels, such as coal and oil, is changing the Earth's climate. Any long-term change in the climate can destroy the habitat of a species. Even a brief change in climate may be too stressful for an organism to survive. For example, if the seas increase in temperature, even briefly, it may be too warm for certain types of fish to reproduce. Ken and Stacy are two engineers discussing their plans about what source of energy they should use to generate electricity in a new city they are helping design. Ken feels that they should use coal since it's reliable, abundant and relatively cheap. Stacy argues that they should use solar power because there is an infinite supply of solar energy. Which person's plan will kill more animals?
Ans: Ken

The Figure below shows decibel levels of several different sounds. As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater. Therefore, a 30-decibel "quiet" room is 10 times louder than a 20-decibel whisper, and a 40-decibel light rainfall is 100 times louder than the whisper. High-decibel sounds are dangerous. They can damage the ears and cause loss of hearing. James is attending a concert. When he first walks in the concert hall there aren't that many people there and it is relatively quiet. As the room fills up it starts to get a bit louder. And when the concert starts its so loud that it is almost painful for him as he is sitting near the speakers. Will the decibel levels have increased or decreased in the time since James arrived at the concert to when the show started?
Ans: increase