Answer the following question given this paragraph: The majority of known elements are classified as metals. Metals are elements that are lustrous, or shiny. They are also good conductors of electricity and heat. Examples of metals include iron, gold, and copper. Fewer than 20 elements are classified as nonmetals. Nonmetals lack the properties of metals. Examples of nonmetals include oxygen, hydrogen, and sulfur. Certain other elements have properties of both metals and nonmetals. They are known as metalloids. Examples of metalloids include silicon and boron. Q: What are the three classifications of elements? Choices: - metals, non-metals and alkaloids - metals, metaloids, and alkaloids - alkaloids, metaloids, and non-metals - metals, non-metals and metaloids A:
metals, non-metals and metaloids
Answer the following question given this paragraph: Atoms have equal numbers of positive protons and negative electrons, so they are neutral in electric charge. Q: Because atoms have equal numbers of positive protons and negative electrons, what kind of electric charge do they possess? Choices: - none - positive - negative - neutral A:
neutral
Q: Answer the following question given this paragraph: The most widely accepted theory explaining how muscle fibers contract is called the sliding filament theory . According to this theory, myosin filaments use energy from ATP to "walk" along the actin filaments with their cross bridges. This pulls the actin filaments closer together. The movement of the actin filaments also pulls the Z lines closer together, thus shortening the sarcomere. Q: What is the most widely accepted theory explaining how muscle fibers contract? Choices: - sliding pigment theoery - sliding tritium theory - sliding carbon theory - sliding filament theory A:
A: sliding filament theory
Question: Answer the following question given this paragraph: Q: Catecholamines are a class of amine hormones synthesised form which amino acid? Choices: - epinephrine - dopamine - phenylalanine - tyrosine A:
Answer: tyrosine
*Question*
Answer the following question given this paragraph: In this lesson, you read how scientists determine the relative ages of sedimentary rock layers. The law of superposition determines which rock layers are younger or older than others. Q: Name the law that determines as to which rock layers are younger or older than others. Choices: - law of gravity - geologic theory - law of apposition - law of superposition A:
**Answer**
law of superposition
*Question*
Answer the following question given this paragraph: Most ecosystems are disturbed too often to attain a final, stable climax community. Q: Most ecosystems are disturbed too often to attain what final, stable status? Choices: - undisrupted community - calm community - even community - climax community A:
**Answer**
climax community