Are people in France nice to Americans? The French are generally very nice & very hospitable people. Just learn a bit of their language, as you’re in “their” country, make the effort to mingle, be polite, because they’re polite & get to know the real locals & you will soon see. Are French people friendly […]

Is food a limiting factor for plants? In the natural world, limiting factors like the availability of food, water, shelter and space can change animal and plant populations. Other limiting factors, like competition for resources, predation and disease can also impact populations. What are the four limiting factors? The common limiting factors in an ecosystem […]

Why are sugar crystals not a mineral? Minerals are inorganic crystals, which are not derived from any living organisms. Crystals can also form from organic compounds. For example, sugar (which comes from plants) can form crystals, but since sugar is composed of organic material, these crystals are not minerals. Is sugar a mineral? For example, […]

What was the period 4.5 billion years ago called? Precambrian time covers the vast bulk of the Earth’s history, starting with the planet’s creation about 4.5 billion years ago and ending with the emergence of complex, multicelled life-forms almost four billion years later. What occurred on Earth 4.6 billion years ago? Approximately 4.6 billion years […]

What causes evaporation to occur? Evaporation happens when a liquid substance becomes a gas. When water is heated, it evaporates. The molecules move and vibrate so quickly that they escape into the atmosphere as molecules of water vapor. Heat from the sun, or solar energy, powers the evaporation process. How do you increase evaporation? Wind […]

Where can CO2 be found? Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, ice caps, glaciers and seawater. It is present in deposits of petroleum and natural […]

What is the changing variable in an experiment? The independent variable is the one that is changed by the scientist. To insure a fair test, a good experiment has only one independent variable. As the scientist changes the independent variable, he or she observes what happens. What is the variable that is altered? Independent variable […]

What happens when two waves overlap? Constructive interference occurs when the crests of one wave overlap the crests of the other wave, causing an increase in wave amplitude. Destructive interference occurs when the crests of one wave overlap the troughs of the other wave, causing a decrease in wave amplitude. When two waves overlap and […]

Where does a delta occur? Deltas are located at river mouths. They usually exist at the mouth of a river entering an ocean. However, deltas can also be found where rivers meet a lake. While less common, sometimes deltas occur inland. Why Delta is formed at the mouth of a river? When large amounts of […]

What is meant by ocean current? The term “current” describes the motion of the ocean. Ocean currents are driven by wind, water density differences, and tides. Oceanic currents describe the movement of water from one location to another. Does the ocean currents flow near the surface of the continental shelf? This chapter discusses the different […]