Q: Q: The rate at which an unstable isotope decays is measured in a unit known as what? Read this paragraph and choose the correct option from the provided answers: The decay of an unstable isotope to a stable element occurs at a constant rate. This rate is different for each parent-daughter isotope pair. The decay rate is measured in a unit called the half-life. The half-life is the time it takes for half of a given amount of an isotope to decay. For example, the half-life of carbon-14 is 5,730 years. Imagine that you start out with 100 grams of carbon-14. In 5,730 years, half of it decays. This leaves 50 grams of carbon-14. Over the next 5,730 years, half of the remaining amount will decay. Now there are 25 grams of carbon-14. How many grams will there be in another 5,730 years? The figure below graphs the rate of decay of a substance ( Figure below ). Choices: - full-life - staying-life - half-time - half-life A:
A: half-life

Q: Q: What term refers to the breaking stress that will cause permanent deformation or fracture of a material? Read this paragraph and choose the correct option from the provided answers: makes it clear that the deformation is proportional to the applied force. Figure 5.13 shows the Hooke's law relationship between the extension L of a spring or of a human bone. For metals or springs, the straight line region in which Hooke's law pertains is much larger. Bones are brittle and the elastic region is small and the fracture abrupt. Eventually a large enough stress to the material will cause it to break or fracture. Tensile strength is the breaking stress that will cause permanent deformation or fracture of a material. Hooke's Law. Choices: - elasticity - malleability - viscosity - tensile strength A:
A: tensile strength

Q: Q: Where do two or more bones of the skeleton meet? Read this paragraph and choose the correct option from the provided answers: Joints are places where two or more bones of the skeleton meet. With the help of muscles, joints allow the body to move with relatively little force. Some joints can move more than others. Choices: - junctures - valves - muscle paths - joints A:
A: joints

Q: Q: Silicon and germanium react with nitrogen at high temperature to form what? Read this paragraph and choose the correct option from the provided answers: The cavities normally contain hydrated cations that are loosely bound to the oxygen atoms of the negatively charged framework by electrostatic interactions. The sizes and arrangements of the channels and cavities differ in different types of zeolites. For example, in zeolite A the aluminosilicate cages are arranged in a cubic fashion, and the channels connecting the cavities intersect at right angles. In contrast, the cavities in faujasite are much larger, and the channels intersect at 120 angles. In these idealized models, the oxygen atoms that connect each pair of silicon atoms have been omitted. Silicon and germanium react with nitrogen at high temperature to form nitrides(M3N4): Equation 22.26. Choices: - oxides - carbonates - isotopes - nitrides A:
A: nitrides