Ques: Q: What is the term for the force of attraction between things that have a mass? Read this paragraph and choose the correct option from the provided answers: Gravity has traditionally been defined as a force of attraction between things that have mass. According to this conception of gravity, anything that has mass, no matter how small, exerts gravity on other matter. Gravity can act between objects that are not even touching. In fact, gravity can act over very long distances. However, the farther two objects are from each other, the weaker is the force of gravity between them. Less massive objects also have less gravity than more massive objects. Choices: - weight - motion - magnetism - gravity A:
Ans: gravity

Ques: Q: Which is the lightest of the widely used structural metals? Read this paragraph and choose the correct option from the provided answers: low, the two metals with the highest ionization energies (beryllium and magnesium) do form compounds that exhibit some covalent characters. Like the alkali metals, the heavier alkaline earth metals impart color to a flame. As in the case of the alkali metals, this is part of the emission spectrum of these elements. Calcium and strontium produce shades of red, whereas barium produces a green color. Magnesium is a silver-white metal that is malleable and ductile at high temperatures. Passivation decreases the reactivity of magnesium metal. Upon exposure to air, a tightly adhering layer of magnesium oxycarbonate forms on the surface of the metal and inhibits further reaction. (The carbonate comes from the reaction of carbon dioxide in the atmosphere. ) Magnesium is the lightest of the widely used structural metals, which is why most magnesium production is for lightweight alloys. Magnesium (shown in Figure 18.6), calcium, strontium, and barium react with water and air. At room temperature, barium shows the most vigorous reaction. The products of the reaction with water are hydrogen and the metal hydroxide. The formation of hydrogen gas indicates that the heavier alkaline earth metals are better reducing agents (more easily oxidized) than is hydrogen. As expected, these metals react with both acids and nonmetals to form ionic compounds. Unlike most salts of the alkali metals, many of the common salts of the alkaline earth metals are insoluble in water because of the high lattice energies of these compounds, containing a divalent metal ion. Choices: - Metal - calcium - potassium - magnesium A:
Ans: magnesium

Ques: Q: What is the study of how and why plants and animals live where they do? Read this paragraph and choose the correct option from the provided answers: Biogeography is the study of how and why plants and animals live where they do. It provides more evidence for evolution. Let's consider the camel family as an example. Choices: - geomorphology - heredity - lithography - biogeography A:
Ans: biogeography

Ques: Q: Most ocean waves are caused by what? Read this paragraph and choose the correct option from the provided answers: A: Most ocean waves are caused by wind blowing across the water. Moving air molecules transfer some of their energy to molecules of ocean water. The energy travels across the surface of the water in waves. The stronger the winds are blowing, the larger the waves are and the more energy they have. Choices: - radiation - animals - gravity - wind A:
Ans:
wind