Answer the following question given this paragraph: Physical chemistry is the study of macroscopic properties, atomic properties, and phenomena in chemical systems. A physical chemist may study such things as the rates of chemical reactions, the energy transfers that occur in reactions, or the physical structure of materials at the molecular level. Q: What is the study of macroscopic properties, atomic properties, and phenomena in chemical systems? Choices: - differential chemistry - thermal chemistry - molecular chemistry - physical chemistry A:
physical chemistry
(Question)
Answer the following question given this paragraph: Earth's internal heat does not depend on the Sun for energy. This heat comes from remnant heat when the planet formed. It also comes from the decay of radioactive elements. Radioactivity is an important source of energy. Q: Decay of what provides some of earth's internal heat? Choices: - ionic elements - decaying elements - radioactive compounds - radioactive elements A:
(Answer)
radioactive elements
Ques: Answer the following question given this paragraph: 2.4 | Inorganic Compounds Essential to Human Functioning By the end of this section, you will be able to: Compare and contrast inorganic and organic compounds Identify the properties of water that make it essential to life Explain the role of salts in body functioning Distinguish between acids and bases, and explain their role in pH Discuss the role of buffers in helping the body maintain pH homeostasis The concepts you have learned so far in this chapter govern all forms of matter, and would work as a foundation for geology as well as biology. This section of the chapter narrows the focus to the chemistry of human life; that is, the compounds important for the body's structure and function. In general, these compounds are either inorganic or organic. An inorganic compound is a substance that does not contain both carbon and hydrogen. A great many inorganic compounds do contain hydrogen atoms, such as water (H2O) and the hydrochloric acid (HCl) produced by your stomach. In contrast, only a handful of inorganic compounds contain carbon atoms. Carbon dioxide (CO2) is one of the few examples. An organic compound, then, is a substance that contains both carbon and hydrogen. Organic compounds are synthesized via covalent bonds within living organisms, including the human body. Recall that carbon and hydrogen are the second and third most abundant elements in your body. You will soon discover how these two elements combine in the foods you eat, in the compounds that make up your body structure, and in the chemicals that fuel your functioning. The following section examines the three groups of inorganic compounds essential to life: water, salts, acids, and bases. Organic compounds are covered later in the chapter. Q: Carbon and what are the second and third most abundant elements in your body? Choices: - helium - mercury - calcium - hydrogen A:
Ans: hydrogen
(Q).
Answer the following question given this paragraph: Cardiac muscle undergoes aerobic respiration patterns, primarily metabolizing lipids and carbohydrates. Myoglobin, lipids, and glycogen are all stored within the cytoplasm. Cardiac muscle cells undergo twitch-type contractions with long refractory periods followed by brief relaxation periods. The relaxation is essential so the heart can fill with blood for the next cycle. The refractory period is very long to prevent the possibility of tetany, a condition in which muscle remains involuntarily contracted. In the heart, tetany is not compatible with life, since it would prevent the heart from pumping blood. Q: What kind of muscle cells undergo twitch-type contractions with long refractory periods followed by brief relaxation periods, allowing the heart to fill with blood for the next cycle? Choices: - nervous muscle - skeletal muscle - smooth muscle - cardiac muscle A:
(A).
cardiac muscle
Ques:Answer the following question given this paragraph: Unfortunately, using energy from nuclear fusion is far from a reality. Scientists are a long way from developing the necessary technology. One problem is raising temperatures high enough for fusion to take place. Another problem is that matter this hot exists only in the plasma state. There are no known materials that can contain plasma, although a magnet might be able to do it. That's because plasma consists of ions and responds to magnetism. You can learn more about research on nuclear fusion at the URL below. Q: In which state does matter need to be for nuclear fusion? Choices: - cells state - solid state - gaseous state - plasma state A:

Ans:plasma state
Answer the following question given this paragraph: Experiments are sometimes hard or even impossible to do. For example, a scientist who is studying an extinct animal cannot experiment with the animal because it no longer exists. The scientist must rely instead on evidence in the natural world, such as fossils that the extinct animal left behind. Q: What can be hard or even impossible to perform in a scientific sense? Choices: - hypothesises - idea - theorys - experiments A:
experiments