If one Tums tablet contains 550. mg of this ingredient and a person takes two tablets a day, how many calcium ions does this person obtain from...

The active ingredient in Tums is calcium carbonate. If a person takes two 550 mg tablets in one day, they have taken 550*2 = 1100 mg of the active ingredient. 

The chemical formula for calcium carbonate is CaCO3. When calcium carbonate ionizes, each molecule separates into one calcium ion and one carbonate ion. So we need to determine how many molecules of calcium carbonate are present in 1100 mg.

To do so, we need to look up the molar mass of calcium carbonate, which is listed as 100.0869 g/mol. One mole contains 6.022 X 10^23 molecules.

First we convert from milligrams to mols, and then from moles to number of molecules, as follows:

1100 mg = 1.1 g

`1.1/100.0869=0.01099 mol`

`0.01099*6.02*10^23= 6.616*10^21`  molecules

Thus, the person will obtain 6.616 X 10^21 calcium ions from the tablets, since one calcium ion is present for every molecule.

"Gentrification is a double-edged sword." It is often productive revitalizing city neighborhoods, but it can impose great costs on certain...

Yes, gentrification is a double-edged sword. When middle- or upper-class families purchase real estate in lower-class neighborhoods and replace existing dilapidated structures with renovated or brand new ones, it does raise the cost of living in those neighborhoods beyond what lower-income families can afford. Those lower-income families, consequently, are forced to move to the very kinds of neighborhoods out of which they were just forced by the circumstances of gentrification, which are beyond their control. That is an unfortunate byproduct of gentrification.

The positive aspects of gentrification can be argued to outweigh the negative consequences. Having lived in Washington, D.C., for many years, I witnessed such processes turn dilapidated neighborhoods into revitalized communities, which benefits the city as a whole because it raises, considerably, the tax base that, in turn, can be used to improve living conditions for those who feel compelled to flee to less-expensive and often more crime-ridden neighborhoods. When communities are "gentrified," new businesses open up, such as restaurants, bars, boutique shops, and so on, to cater to this more affluent clientele, which provides jobs for lower-income individuals. Neighborhoods once avoided by middle- and upper-class families because of the fears of crime and the depressing nature of slums become desired destinations for young upwardly-mobile families.

Gentrification's victims, such as the ethnic-oriented cultures that existed in these neighborhoods, are, indeed, replaced by other, sometimes more culturally-diverse inhabitants. It is often socioeconomic class rather than ethnicity that determines the demographic transformations that occur in communities where gentrification occurs. Interestingly, in Washington, D.C., gentrification was often initiated by the gay and lesbian communities, who took it upon themselves to buy dilapidated, often abandoned housing developments and turn them into refurbished, vibrant neighborhoods.

It is not only gentrification that affects neighborhoods, either. Often, the development of a new venue for local professional sports franchises--in effect, construction of new stadiums and arenas--has as much effect on lower-income families as does gentrification. The most affordable and desirable real estate, from a geographical perspective, is often in the worst neighborhoods. Real estate values in such neighborhoods are, unsurprisingly, relatively low, and such neighborhoods are located in inner-city areas where city officials desperately hope to entice new businesses. Once older, lower-income housing developments are torn down to make way for the new sports arena, multitudes of small businesses sprout up to profit off of the waves of humanity expected to frequent the stadiums and arenas. New, expensive housing developments are similarly constructed nearby that are, by design, beyond the financial reach of all but the wealthy and upper-midde-class.

In short, displacement of lower-income families by the process of gentrification can be--but not always is--deleterious to the interests of those families. The benefits to the city as a whole, however, almost always outweigh the negatives.

How are electromagnetics used in recycling plants?

The goal of recycling plant is to find useful products from the materials discarded by the society and to recycle them, so that they can be reused, either directly or indirectly (after some processing). One of the easiest ways to achieve this goal is by separating the waste into various categories, according to their properties. Then, the segregated waste can be processed accordingly. 

Electromagnetics are commonly used for separating magnetic waste materials (such as iron-based waste) from the combined waste. Electromagets are used for this purpose. The underlying idea is that magnetic field exists when there is an electric current through the magnet and disappears when the current is turned off. The magnet is brought in contact or close proximity of combined waste, and the electricity is turned on. All the magnetic material would be attached to the electromagnet. This electromagnet would then be directed away from the combined waste and the electricity will be turned off. As soon as the electricity is turned off, the electromagnet will cease to have magnetic properties and all the magnetic waste (attached to the magnet) will fall down and collected separately. This magnetic waste can then be processed accordingly.

Hope this helps. 

In what ways do spoken language and written language differ?

Of course it depends of the person, but generally spoken language is much less formal than written language. People have higher standards for grammar, usage, etc when they are reading than when they are listening. Additionally, slang is far more accepted in spoken language than in written language. To get more technical about the subject, in English there are primarily two types of words: words that are romantic in origin and words that are Germanic in origin. Romantic words, which come from Latin, are much more common in written English than they are in spoken English. This is because usually we associate both Latin words and written language with a more formal or academic environment. Germanic words are more common in spoken language. We usually think of these words as being more informal.

How did Rikki get his name in "Rikki-tikki-tavi? What literary term is this?

Rikki got his name from the sound he makes, an example of onomatopoeia.

Onomatopoeia is a sound device where a word is used that makes a sound.  The words are usually spelled to represent the sound.  In this case, the sound is the war cry of the mongoose.

His eyes and the end of his restless nose were pink; he could scratch himself anywhere he pleased, with any leg, front or back, that he chose to use; he could fluff up his tail till it looked like a bottle-brush, and his war-cry, as he scuttled through the long grass, was: ``Rikk-tikk-tikki-tikki-tchk!''

Since Rikki is an animal, it makes sense that he might get his name from the sound of the noise that he makes.  A mongoose is a very brave creature, and according to Kipling a mongoose is also incredibly curious.  While snakes are the natural enemy of the mongoose, Rikki is not even afraid of the cobras.

He was afraid for the minute; but it is impossible for a mongoose to stay frightened for any length of time, … and he knew that all a grown mongoose's business in life was to fight and eat snakes.

Rikki makes his war cry when he is on the hunt.  Throughout the story, Rikki successfully kills three snakes.  He kills the small but deadly Karait first, and then follows it up with the successful deaths of the two cobras, Nag and his wife Nagaina.  He protects the humans that are living in the house, and the other animals in the garden.

Personification is often used in stories that serve as fables.  Animals are given human traits and values.  In this story, we learn the effects of colonialism through Rikki and the cobras.  Rikki comes in and believes he owns the place.  His war cry is the death knell to the original inhabitants of the garden, the cobras.  While we may cheer for the mongoose, it is important to remember that the snakes were there first.

How do you think the physical properties of carbon, hydrogen, and oxygen change when they combine to form sugar?

Carbon, hydrogen and oxygen are the elements that make up sugars including sucrose, white table sugar.

Carbon is a solid at room temperature and is found in three different forms: Coal, graphite and diamond. Graphite and coal are soft while diamond, which has covalent network bonding, is a very hard material.  All are insoluble in water. Graphite and coal are dark gray to black. Carbon has a melting point of about 3500 degrees C.

Oxygen and hydrogen are both colorless gases at room temperature, with boiling points of -183 and -253 degrees C respectively.

The sugars that contain these three elements have very different properties. Sucrose and glucose are water-soluble colorless crystalline solids that appear white in the granulated form. Sucrose has a melting point of 186 degrees C and glucose melts at 146 degrees C. Glucose is  more often available as  a thick, syrup-like aqueous solution. The molar masses of sugars are much higher than those of their constituent elements:

sucrose - 342 g/mol

glucose - 180 g/mol

hydrogen gas - 2 g/mol

oxgen gas - 32 g/mol

carbon - 12 g/mol

There are other sugars with the same chemical formulas as sucrose and glucose, but different structural formulas. They have physical properties similar to those of sucrose and glucose.

Note that although sugars contain the elements carbon, hydrogen and oxygen, they aren't produced directly from their elements. Sugars are plant products that are produced from the carbon dioxide gas and water that plants take in.

What does Uncle Jack think of the fight between Francis and Scout after talking to Scout?

After he confers with Scout about her verbal exchanges with Francis, Uncle Jack understands why she has acted as she has towards her cousin.

Subsequent to Scout's punch to the mouth of Francis, Atticus loads her into their car and they return home from Finch's Landing where they have spent Christmas. But, because Scout has been so angered that Jack does not let her explain why she has struck Francis in the mouth, she has told her uncle that she will never speak to him again for having been so unfair. Troubled by Scout's words, Jack decides to drive to the Finches' and clear up any misunderstanding. When he knocks on the door, Scout angrily tells him, "Go away!" But he insists on resolving their conflict. So, when he allows Scout to explain that Francis has called her father a "n*****r-lover and repeated part of what he has overheard--

"Atticus'd be the ruination of the family an' he let Jem an me run wild...." (Ch. 9)--

Now Uncle Jack becomes disturbed not by Scout, but by the words of Francis. He then promises Scout,

"We'll see about this....I've a good mind to go out there tonight.....The idea of--wait'll I get my hands on that boy...." (Ch.9)

Despite her satisfaction that Uncle Jack now understands, Scout begs him to not tell Atticus about her fight with Francis, explaining that she would prefer that her father believe that their fight was about something else, rather than the upcoming trial. He agrees and good relations are resumed as her physician uncle tends to Scout's skinned knuckles.