Q: What makes up the mass number of an atom? Read this paragraph and choose the correct option from the provided answers: The mass number is the number of protons plus the number of neutrons in an atom. For example, most atoms of helium have 2 neutrons, so their mass number is 2 + 2 = 4. This mass number means that an atom of helium has a mass of about 4 amu. Choices: - electrons and neutrons - atoms and neutrons - molecules and electrons - protons and neutrons A:
protons and neutrons
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Q: The volume of a gas is comprised of about 10% matter. what is the rest? Read this paragraph and choose the correct option from the provided answers: The volume of a gas contains only about 10% matter, with the rest being empty space. Hsub is equal to Hvap. Choices: - open space - instead space - normal space - empty space A:
empty space
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Q: What structure is an organelle that contains enzymes that break down and digest unneeded cellular components? Read this paragraph and choose the correct option from the provided answers: Lysosomes Some of the protein products packaged by the Golgi include digestive enzymes that are meant to remain inside the cell for use in breaking down certain materials. The enzyme-containing vesicles released by the Golgi may form new lysosomes, or fuse with existing, lysosomes. A lysosome is an organelle that contains enzymes that break down and digest unneeded cellular components, such as a damaged organelle. (A lysosome is similar to a wrecking crew that takes down old and unsound buildings in a neighborhood. ) Autophagy ("self-eating") is the process of a cell digesting its own structures. Lysosomes are also important for breaking down foreign material. For example, when certain immune defense cells (white blood cells) phagocytize bacteria, the bacterial cell is transported into a lysosome and digested by the enzymes inside. As one might imagine, such phagocytic defense cells contain large numbers of lysosomes. Under certain circumstances, lysosomes perform a more grand and dire function. In the case of damaged or unhealthy cells, lysosomes can be triggered to open up and release their digestive enzymes into the cytoplasm of the cell, killing the cell. This "self-destruct" mechanism is called autolysis, and makes the process of cell death controlled (a mechanism called "apoptosis"). Choices: - peroxisome - tissue - centrosome - lysosome A:
lysosome
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Q: What are electrons at the outermost energy level of an atom are called? Read this paragraph and choose the correct option from the provided answers: Electrons at the outermost energy level of an atom are called valence electrons. They determine many of the properties of an element. That's because these electrons are involved in chemical reactions with other atoms. Atoms may share or transfer valence electrons. Shared electrons bind atoms together to form chemical compounds. Choices: - core electrons - ions - shell electrons - valence electrons A:
valence electrons
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