Answer the following question given this paragraph: A compound is a unique substance that forms when two or more elements combine chemically. Compounds form as a result of chemical reactions. The elements in compounds are held together by chemical bonds. A chemical bond is a force of attraction between atoms or ions that share or transfer valence electrons. For a video introduction to compounds, go to this URL: http://www. youtube. com/watch?v=-HjMoTthEZ0 . Q: What type of reactions form compounds? Choices: - mineral reactions - consumption reactions - physical reactions - chemical reactions A:
chemical reactions
(Question)
Answer the following question given this paragraph: The mesosphere is the layer above the stratosphere. It rises to about 85 kilometers (53 miles) above the surface. Temperature decreases with altitude in this layer. Q: What is the layer above the mesophere called? Choices: - exosphere - thermosphere - troposphere - stratosphere A:
(Answer)
stratosphere
Ques: Answer the following question given this paragraph: Diseases caused by roundworms are more common in developing countries. Many parasitic diseases caused by roundworms result from poor personal hygiene. Contributing factors may include. Q: More common in developing countries, parasitic diseases caused by roundworms often result from poor practice of what? Choices: - agriculture - education - preventative medicine - personal hygiene A:
Ans: personal hygiene
(Q).
Answer the following question given this paragraph: Common Structures of Binary Compounds As shown in part (a) in Figure 12.8 "Holes in Cubic Lattices", a simple cubic lattice of anions contains only one kind of hole, located in the center of the unit cell. Because this hole is equidistant from all eight atoms at the corners of the unit cell, it is called acubic hole. An atom or ion in a cubic hole therefore has a coordination number of 8. Many ionic compounds with relatively large cations and a 1:1 cation:anion ratio have this structure, which is called the cesium chloride structure (Figure 12.9 "The Cesium Chloride Structure") because CsCl is a common example. Q: Many ionic compounds with relatively large cations and a 1:1 cation:anion ratio have this structure, which is called the what? Choices: - boron chloride structure - hydrocarbon structure - analogous structure - cesium chloride structure A:
(A).
cesium chloride structure
Ques:Answer the following question given this paragraph: 6.2 Potential, Kinetic, Free, and Activation Energy Energy comes in many different forms. Objects in motion do physical work, and kinetic energy is the energy of objects in motion. Objects that are not in motion may have the potential to do work, and thus, have potential energy. Molecules also have potential energy because the breaking of molecular bonds has the potential to release energy. Living cells depend on the harvesting of potential energy from molecular bonds to perform work. Free energy is a measure of energy that is available to do work. The free energy of a system changes during energy transfers such as chemical reactions, and this change is referred to as G. The G of a reaction can be negative or positive, meaning that the reaction releases energy or consumes energy, respectively. A reaction with a negative G that gives off energy is called an exergonic reaction. One with a positive G that requires energy input is called an endergonic reaction. Exergonic reactions are said to be spontaneous, because their products have less energy than their reactants. The products of endergonic reactions have a higher energy state than the reactants, and so these are nonspontaneous reactions. However, all reactions (including spontaneous -G reactions) require an initial input of energy in order to reach the transition state, at which they'll proceed. This initial input of energy is called the activation energy. Q: What kind of energy is specifically defined as the energy that is available to do work? Choices: - used - new - old - free A:

Ans:free
Question: Answer the following question given this paragraph: Q: Monosaccharides, particularly glucose, are major nutrients for what? Choices: - proteins - photosynthesis - lipids - cells A:
Answer:
cells