Answer the following question given this paragraph: Depending on the surrounding conditions, normal matter usually exists as one of three phases: solid, liquid, or gas. A phase change is a physical process in which a substance goes from one phase to another. Usually the change occurs when adding or removing heat at a particular temperature, known as the melting point or the boiling point of the substance. The melting point is the temperature at which the substance goes from a solid to a liquid (or from a liquid to a solid). The boiling point is the temperature at which a substance goes from a liquid to a gas (or from a gas to a liquid). The nature of the phase change depends on the direction of the heat transfer. Heat going into a substance changes it from a solid to a liquid or a liquid to a gas. Removing heat from a substance changes a gas to a liquid or a liquid to a solid. Two key points are worth emphasizing. First, at a substance's melting point or boiling point, two phases can exist simultaneously. Take water (H2O) as an example. On the Saylor URL: http://www. saylor. org/books. Q: Depending on the surrounding conditions, normal matter usually exists as one of three phases: solid, liquid, or this? Choices: - fluid - crystal - ice - gas A:
gas
Answer the following question given this paragraph: Most plants continue to grow as long as they live. They grow through a combination of cell growth and cell division (mitosis). The key to plant growth is meristem, a type of plant tissue consisting of undifferentiated cells that can continue to divide and differentiate. Meristem allows plant stems and roots to grow longer (primary growth) and wider (secondary growth). Q: What is a type of plant tissue consisting of undifferentiated cells that can continue to divide and differentiate? Choices: - epidermis - cambium - ganglion - meristem A:
meristem
Q: Answer the following question given this paragraph: Because radon is a noble gas, it is inert and generally unreactive. Despite this, exposure to even low concentrations of radon in air is quite dangerous. Describe the physical consequences of exposure to radon gas. Why are people who smoke more susceptible to these effects?. Q: Radon is inert and generally unreactive because it is which kind of gas? Choices: - ignoble gas - transitive gas - ideal gas - noble gas A:
A: noble gas
Question: Answer the following question given this paragraph: The first few species to colonize a disturbed area are called pioneer species. In primary succession, pioneer species must be organisms that can live on bare rock. They usually include bacteria and lichens (see Figure below ). Along with wind and water, the pioneer species help weather the rock and form soil. Once soil begins to form, plants can move in. The first plants are usually grasses and other small plants that can grow in thin, poor soil. As more plants grow and die, organic matter is added to the soil. This improves the soil and helps it hold water. The improved soil allows shrubs and trees to move into the area. Q: The first few species to colonize a disturbed area are called what? Choices: - producer species - original species - colonization species - pioneer species A:
Answer: pioneer species
*Question*
Answer the following question given this paragraph: Excess water is absorbed from food waste in the large intestine before it passes out of the body through the anus as feces. Trillions of helpful bacteria also live in the large intestine. They carry out important roles, such as making vitamins. Q: What is absorbed from food waste in the large intestine before it passes out of the body as feces? Choices: - distilled water - dependent water - inactive water - excess water A:
**Answer**
excess water
*Question*
Answer the following question given this paragraph: The product of a wave's wavelength () and its frequency (), , is the speed of the wave. Thus, for electromagnetic radiation in a vacuum: c = 2.998 10 8 ms 1 = Wavelength and frequency are inversely proportional: As the wavelength increases, the frequency decreases. The inverse proportionality is illustrated in Figure 6.3. This figure also shows the electromagnetic spectrum, the range of all types of electromagnetic radiation. Each of the various colors of visible light has specific frequencies and wavelengths associated with them, and you can see that visible light makes up only a small portion of the electromagnetic spectrum. Because the technologies developed to work in various parts of the electromagnetic spectrum are different, for reasons of convenience and historical legacies, different units are typically used for different parts of the spectrum. For example, radio waves are usually specified as frequencies (typically in units of MHz), while the visible region is usually specified in wavelengths (typically in units of nm or angstroms). Q: The product of a wave's wavelength and its frequency is what? Choices: - trough - velocity - amplitude - speed A:
**Answer**
speed