Q: Hydrogen gas is generated by the reaction of nitric acid and what else? Read this paragraph and choose the correct option from the provided answers: E XA MP L E 1 7 Hydrogen gas is generated by the reaction of nitric acid and elemental iron. The gas is collected in an inverted 2.00 L container immersed in a pool of water at 22C. At the end of the collection, the partial pressure inside the container is 733 torr. How many moles of H2 gas were generated?. Choices: - gaseous iron - martian iron - carbon - elemental iron A:
elemental iron

Q: What plays the same role in rotational motion that force plays in linear motion. Read this paragraph and choose the correct option from the provided answers: of pivot point, and so we choose the pivot point to simplify the solution of the problem. Second, the acceleration due to gravity canceled in this problem, and we were left with a ratio of masses. This will not always be the case. Always enter the correct forcesdo not jump ahead to enter some ratio of masses. Third, the weight of each child is distributed over an area of the seesaw, yet we treated the weights as if each force were exerted at a single point. This is not an approximationthe distances r 1 and r 2 are the distances to points directly below the center of gravity of each child. As we shall see in the next section, the mass and weight of a system can act as if they are located at a single point. Finally, note that the concept of torque has an importance beyond static equilibrium. Torque plays the same role in rotational motion that force plays in linear motion. We will examine this in the next chapter. Take-Home Experiment Take a piece of modeling clay and put it on a table, then mash a cylinder down into it so that a ruler can balance on the round side of the cylinder while everything remains still. Put a penny 8 cm away from the pivot. Where would you need to put two pennies to balance? Three pennies?. Choices: - efficiency - frame - fulcrum - torque A:
torque

Q: Q: The enzyme pepsin works only in the presence of what? Read this paragraph and choose the correct option from the provided answers: The enzyme pepsin works only in the presence of acid. A strong acid is secreted into the stomach. It provides the acid that pepsin needs. You will learn about acids in the next chapter, "Chemistry of Solutions. " Vinegar and lemon juice are two common acids. Choices: - carbohydrates - sodium - oxygen - acid A:
A: acid

Question: Q: Ionic bonds are electrostatic attractions between two oppositely charged what? Read this paragraph and choose the correct option from the provided answers: Ionic bonds are electrostatic attractions between two oppositely charged ions. Ions can be formed and then bonded when metal atoms donate their valence electrons to nonmetal atoms. Choices: - molecules - gasses - compounds - ions A:
Answer: ions

*Question*
Q: What shape is each face of a tetrahedron? Read this paragraph and choose the correct option from the provided answers: In order to maximize their distance from one another, the four groups of bonding electrons do not lie in the same plane. Instead, each of the hydrogen atoms lies at the corners of a geometrical shape called a tetrahedron. The carbon atom is at the center of the tetrahedron. Each face of a tetrahedron is an equilateral triangle. Choices: - asymmetric triangle - oval - trapezoid - equilateral triangle A:
**Answer**
equilateral triangle

Q: Q: The most abundant formed elements in blood, erythrocytes are red, biconcave disks packed with an oxygen-carrying compound called this? Read this paragraph and choose the correct option from the provided answers: 18.3 Erythrocytes The most abundant formed elements in blood, erythrocytes are red, biconcave disks packed with an oxygen-carrying compound called hemoglobin. The hemoglobin molecule contains four globin proteins bound to a pigment molecule called heme, which contains an ion of iron. In the bloodstream, iron picks up oxygen in the lungs and drops it off in the tissues; the amino acids in hemoglobin then transport carbon dioxide from the tissues back to the lungs. Erythrocytes live only 120 days on average, and thus must be continually replaced. Worn-out erythrocytes are phagocytized by macrophages and their hemoglobin is broken down. The breakdown products are recycled or removed as wastes: Globin is broken down into amino acids for synthesis of new proteins; iron is stored in the liver or spleen or used by the bone marrow for production of new erythrocytes; and the remnants of heme are converted into bilirubin, or other waste products that are taken up by the liver and excreted in the bile or removed by the kidneys. Anemia is a deficiency of RBCs or hemoglobin, whereas polycythemia is an excess of RBCs. Choices: - plasma - hydrogen - pus - hemoglobin A:
A: hemoglobin