Answer the following question given this paragraph: The age of a rock in years is its absolute age. The main evidence for absolute age comes from radiometric dating methods, such as carbon-14 dating. These methods depend on radioactive decay. Q: Radiometric dating methods, such as carbon-14 dating depend on what type of decay? Choices: - microwave - carbon - nuclear - radioactive A:
radioactive
Answer the following question given this paragraph: Additionally, the yellow marrow, which is found in the central cavity of long bones along with red marrow, serves as a storage site for fat. 42 Structurally, the femur is a long bone, meaning its length is greater than its width, while the patella, a sesamoid bone, is small and round. Functionally, the femur acts as a lever, while the patella protects the patellar tendon from compressive forces. 44 The densely packed concentric rings of matrix in compact bone are ideal for resisting compressive forces, which is the function of compact bone. The open spaces of the trabeculated network of spongy bone allow spongy bone to support shifts in weight distribution, which is the function of spongy bone. 46 A single primary ossification center is present, during endochondral ossification, deep in the periosteal collar. Like the primary ossification center, secondary ossification centers are present during endochondral ossification, but they form later, and there are two of them, one in each epiphysis. 48 The internal callus is produced by cells in the endosteum and is composed of a fibrocartilaginous matrix. The external callus is produced by cells in the periosteum and consists of hyaline cartilage and bone. 50 Astronauts floating in space were not exerting significant pressure on their bones; they were "weightless. " Without the force of gravity exerting pressure on the bones, bone mass was lost. To alleviate this condition, astronauts now do resistive exercise designed to apply forces to the bones and thus help keep them healthy. 52 Under "normal" conditions, receptors in the parathyroid glands bind blood calcium. When the receptors are full, the parathyroid gland stops secreting PTH. In the condition described, the parathyroid glands are not responding to the signal that there is sufficient calcium in the blood and they keep releasing PTH, which causes the bone to release more calcium into the blood. Ultimately, the bones become fragile and hypercalcemia can result. Q: When it was found that, without the force of gravity exerting pressure on the bones, bone mass was lost in astronauts, what kind of exercise provided an antidote? Choices: - aerobic - anaerobic - sedentary - resistive A:
resistive
Q: Answer the following question given this paragraph: One problem with current methods of aluminum production is the generation of environmental contaminants. Hydrogen fluoride gas is an extremely corrosive and toxic byproduct that must be trapped and neutralized. Other fluorides and metals contaminants can also pollute water, soil, and air if not carefully managed. Q: What is one problem with current methods of aluminum production? Choices: - food shortages - competition - recycling is cheap - environmental contaminants A:
A: environmental contaminants
Question: Answer the following question given this paragraph: Lightning occurs when there is a sudden discharge of static electricity between a cloud and the ground. Q: What occurs when there is a sudden discharge of static electricity between a cloud and the ground? Choices: - updraft - wind - rain - lightning A:
Answer: lightning
*Question*
Answer the following question given this paragraph: 2Al(s) + Fe2O3(s) 2Fe(s) + Al2O3(s) + heat to indicate that heat is one of the products. Chemical equations in which heat is shown as either a reactant or a product are called thermochemical equations. In this reaction, the system consists of aluminum, iron, and oxygen atoms; everything else, including the container, makes up the surroundings. During the reaction, so much heat is produced that the iron liquefies. Eventually, the system cools; the iron solidifies as heat is transferred to the surroundings. A process in which heat (q) is transferred from a system to its surroundings is described as exothermic. By convention, q < 0 for an exothermic reaction. Q: Chemical equations in which heat is shown as either a reactant or a product are called what? Choices: - hydroelectric equations - thorium equations - feedstock equations - thermochemical equations A:
**Answer**
thermochemical equations
Q: Answer the following question given this paragraph: This model for metallic bonding explains some of the physical properties of metals. Metals conduct electricity and heat very well because of their free-flowing electrons. As electrons enter one end of a piece of metal, an equal number of electrons flow outward from the other end, allowing an electrical current to pass through the material with minimal resistance. Additionally, because the electron "glue" that holds the metal atoms together is very easy to deform and reshape, bulk metals can be easily hammered, bent, and pulled without breaking apart. Q: Free-flowing electrons enable what materials to conduct electricity and heat very well? Choices: - noble gases - alloys - acids - metals A:
A: metals