Read Aloud
1.Actinium was first recognized in 1899 by André Debierne in uranium residues from pitchblende after the radium was extracted by Pierre and Marie Curie. It was later found to be identical with an element discovered in 1902 by Fritz Giesel and which he called emanium. Actinium is in Group 3 of the periodic table. Its chemical properties are similar to those of lanthanum and of members of the actinide series, of which it is usually considered the first member.
2.Alkali metals, metals found in Group 1 of the periodic table. Compared to other metals they are soft and have low melting points and densities. Alkali metals are powerful reducing agents and form univalent compounds. All react violently with water, releasing hydrogen and forming hydroxides. They tarnish rapidly even in dry air. They are never found uncombined in nature. In order of increasing atomic number the alkali metals are lithium, sodium, potassium, rubidium, cesium, and francium.
3.Bluestone, common name for the blue, crystalline heptahydrate of cupric sulfate called chalcanthite, a minor ore of copper. It also refers to a fine-grained, light to dark colored blue-gray sandstone. Deposits are extensively quarried as flagstone in New York and Pennsylvania and used commercially for buildings and paving stone.
4.The reason that acid-base reactions are so important is that many of the things you come into contact with on a daily basis are either acids or bases. Most fruits are acids, as are carbonated beverages, tea, and battery acid. Common household bases include baking soda, ammonia, soap, and antacids. As you’ll find, acids and bases really aren’t that difficult to understand once you get the hang of them.
5.Dynamite, explosive made from nitroglycerin and an inert, porous filler such as wood pulp, sawdust, kieselguhr, or some other absorbent material. The proportions vary in different kinds of dynamite; often ammonium nitrate or sodium nitrate is added. The mass is usually pressed in cylindrical forms and wrapped in an appropriate material, e.g., paper or plastic. The charge is set off with a detonator. Dynamite was discovered by Alfred B. Nobel in 1866.
6.Gasoline or petrol, light, volatile mixture of hydrocarbons for use in the internal-combustion engine and as an organic solvent, obtained primarily by fractional distillation and “cracking” of petroleum, but also obtained from natural gas, by destructive distillation of oil shales and coal, and by a process that converts methanol to gasoline using zeolite as a catalyst.
7.There are five blends of gasoline marketed in the United States. Conventional gasoline, the most widely available, is sold where air quality is satisfactory; since 1992, it has been formulated to evaporate more slowly in hot weather so as to reduce smog, and it now contains detergent additives to reduce engine deposits. Winter oxygenated gasoline,introduced in 1992, is formulated as conventional gasoline with oxygen-rich chemicals added, such as ethanol.
8.Many important compounds are derived from hydrocarbons, either by substitution or replacement by some other chemical group or element of one or more of the hydrogen atoms of the hydrocarbon molecule, or by the addition of some element or group to a double or triple bond (in an unsaturated hydrocarbon). Such derivatives include alcohols, aldehydes, ethers, carboxylic acids, and halocarbons.
9.Cooling systems in one of the reactors at the Fukushima Daiichi Nuclear Power Station in the Fukushima prefecture on the east coast of Japan failed shortly after the earthquake, causing a nuclear crisis. This initial reactor failure was followed by an explosion and eventual partial meltdowns in two reactors, then by a fire in another reactor which released radioactivity directly into the atmosphere. The nuclear troubles were not limited to the Daiichi plant; three other nuclear facilities also reported problems. More than 200,000 residents were evacuated from affected areas.
10.A tsunami is a series of huge waves that occur as the result of a violent underwater disturbance, such as an earthquake or volcanic eruption.The waves may travel in the open sea as fast as 450 miles per hour. As they travel in the open ocean, tsunami waves are generally not particularly large—hence the difficulty in detecting the approach of a tsunami. But as these powerful waves approach shallow waters along the coast, their velocity is slowed and they consequently grow to a great height before smashing into the shore. They can grow as high as 100 feet; the Indian Ocean tsunami generated waves reaching 30 feet.
11.Hurricanes are the most powerful storms on Earth. Whether called typhoons in the western Pacific or cyclones in the Indian Ocean, damage and destruction result wherever they strike land. These storms develop under different conditions than the everyday storm—they’re also far less predictable.
12.Although the mesoscale level of weather action is small in stature, it certainly is huge in impact. The most violent weather on the face of the earth takes place within this scale. Tall cumulonimbus clouds turn into violent thunderstorms, delivering strong winds, torrential rains, and damaging lightning. At the extreme, these clouds can begin to spin and form tornadoes. This severe weather strikes throughout the world, but the United States seems to be world capital for violent thunderstorms and tornadoes. A unique convergence of forces makes them happen with amazing frequency.
13.These are the four basic cloud types. There are also combinations that show up at different elevations. The classification scheme that so far has been based solely on a cloud’s appearance now becomes a little more sophisticated. The types are combined and categorized into groups of high, middle, low clouds, and clouds that extend through all elevations
14.A good prediction must begin with a set of observations. The atmosphere needs to be measured, weighed, and analyzed before we can begin to make a forecast. We’ve already checked out the basic weather variables in “Bring on the Rain,” and looked at how they can be measured. So this is going to be a partial review, but we’ll take a more detailed look at how weather data is collected and transmitted from one part of the world to another.
15.Atmosphere, the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the atmospheres of other planets and satellites are known, only the earth’s atmosphere has been well studied, the science of which is called meteorology.
16.The most common instrument for measuring relative humidity is the sling psychrometer. It consists of two thermometers mounted next to each other. One thermometer has a wet wick attached to its bulb, and the other is dry. The wick is moistened with water at air temperature. The two thermometers are attached to a handle, which is swung around. Water evaporates off the moist wick, causing a lowering of temperature on that bulb—called, for obvious reasons, the wet bulb.
17.History rubs shoulders and often overlaps with many other areas of research, from myths and epics to the social sciences, including economics, politics, biography, demography, and much else besides.Some histories are almost pure narratives, while others go in for detailed, tightly-focused analyses of, for example, the parish records of a Cornish village in the 16th century
18.There are many kinds of pond, but nearly all are small bodies of shallow, stagnant water in which
plants with roots can grow. Water movement is slight and temperatures fluctuate widely. The
wealth of plants ensures that during daylight hours oxygen is plentiful. However, at night, when
photosynthesis no longer takes place, oxygen supplies can fall very low.
19.Before the time of Alexander the Great, the only eastern people who could be compared with
the Greeks in the fields of science and philosophy were from the Indian sub-continent. However,
because so little is known about Indian chronology, it is difficult to tell how much of their science
was original and how much was the result of Greek influence.
20.While far fewer people these days write letters and therefore have less use for stamps, there are still
a few categories of stamp which attract collectors. Stamps in common use for an indefinite period -
until the price goes up - are called "definitive" issues, while a more collectible type of stamp is the
"commemorative" issue, honoring people, events and anniversaries.
21.In the second quarter of the 19th century, a rapidly growing middle class created a great demand
for furniture production. Yet at this stage, while machines were used for certain jobs, such as
carved decoration, there was no real mass production. The extra demand was met by numerous
woodworkers. Mass production came later and the quality of domestic furniture declined.
22.In the Middle Ages, the design and use of flags were considered a means of identifying social
status. Flags were, therefore, the symbols not of nations, but of the nobility. The design of each flag
resembled the "devices" on the noble's Coat of Arms, and the size of the flag was an indication of
how high the owner stood in the nobility.
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