Answer the following question given this paragraph: All alkali metals are very soft and can be cut easily with a knife. Due to their high reactivity, they must be stored under oil to prevent them from reacting with oxygen or water vapor in the air. The reactions between alkali metals and water are particularly vigorous and include the rapid production of large quantities of hydrogen gas. Alkali metals also react easily with most nonmetals. All of the alkali metals are far too reactive to be found in nature in their pure elemental form. For example, all naturally occurring sodium exists as a compound, such as sodium chloride (table salt). Q: The reactions between alkali metals and water are particularly vigorous and include the rapid production of large quantities of what gas? Choices: - helium - oxygen - carbon - hydrogen A:
hydrogen
(Question)
Answer the following question given this paragraph: The blood also carries hormones, which are chemical messenger molecules produced by organs of the endocrine system, through your body. Hormones are produced in one area of your body and have an effect on another area. To get to that other area, they must travel through your blood. An example is the hormone adrenaline, produced by the adrenal glands on top of the kidneys. Adrenaline has multiple effects on the heart (it quickens the heart rate), on muscles and on the airway. Q: What system of the body is responsible for producing hormones? Choices: - nervous system - regulatory system - homeostasis system - endocrine system A:
(Answer)
endocrine system
Ques: Answer the following question given this paragraph: Fuels According to the law of conservation of energy, energy can never actually be "consumed"; it can only be changed from one form to another. What is consumed on a huge scale, however, are resources that can be readily converted to a form of energy that is useful for doing work. As you will see in Chapter 18 "Chemical Thermodynamics", energy that is not used to perform work is either stored as potential energy for future use or transferred to the surroundings as heat. A major reason for the huge consumption of energy by our society is the low efficiencyof most machines in transforming stored energy into work. Efficiency can be defined as the ratio of useful work accomplished to energy expended. Automobiles, for example, are only about 20% efficient in converting the energy stored in gasoline to mechanical work; the rest of the energy is released as heat, either emitted in the exhaust or produced by friction in bearings and tires. The production of electricity by coal- or oilpowered steam turbines is significantly more efficient (Figure 5.17 "Electricity from Coal"): about 38% of the energy released from combustion is converted to electricity. In comparison, modern nuclear power plants can be more than 50% efficient. Figure 5.17 Electricity from Coal. Q: Fuels according to the law of what, can never actually be "consumed"; it can only be changed from one form to another? Choices: - use of energy - expansion of energy - difference of energy - conservation of energy A:
Ans: conservation of energy
(Q).
Answer the following question given this paragraph: Dwarf galaxies are small galaxies containing "only" a few million to a few billion stars. Most dwarf galaxies are irregular in shape. However, there are also dwarf elliptical galaxies and dwarf spiral galaxies . Dwarf galaxies are the most common type in the Universe. However, because they are relatively small and dim, we don't see as many dwarf galaxies as we do their full-sized cousins. Q: Smaller sized galaxies are known as what? Choices: - nebula - black holes - constellations - dwarf galaxies A:
(A).
dwarf galaxies
Ques:Answer the following question given this paragraph: In all types of mechanical waves, energy moves from one place to another while the media carrying the wave only vibrates back and forth in position. One type of mechanical wave is the transverse wave . In the case of transverse waves, the movement of the medium is perpendicular to the direction of the energy movement. Q: In the case of transverse waves, the movement of the medium is perpendicular to the direction of the what? Choices: - friction movement - pressure movement - fuel movement - energy movement A:

Ans:energy movement
Question: Answer the following question given this paragraph: We use simple machines because they give us a mechanical advantage . Mechanical advantage is a measurement of the force amplification of a machine. In ideal machines, where there is no friction and the input work and output work are the same,. Q: What is is a measurement of the force amplification of a machine? Choices: - mechanical push - mechanical pull - force multiplier - mechanical advantage A:
Answer:
mechanical advantage