Read the article "Chicago's International Airports" and answer the question. Chicago is a transportation hub. There are several airports in or near the city. O'Hare International and Midway International are two of the busiest airports in the area. They share many similarities and have some key differences. The city's busiest airport is O'Hare International Airport. It is located northwest of downtown Chicago. To travel between the airport's four terminals, passengers use the automated Airport Transit System. These trains travel over 2.7 miles of track and can carry 2,400 passengers in an hour. Other options for moving between terminals include the pedestrian tunnels and the Terminal Transfer Bus. O'Hare has about 1,028 direct domestic flights and 126 direct international flights each day. In contrast to O'Hare, Midway International Airport is a relatively small airport located southwest of downtown Chicago. The airport only has three concourses, making travel between gates easy and efficient. The facility has approximately 238 direct domestic flights and 12 direct international flights each day.

Both airports feature a variety of artwork, restaurants, and activities for people to experience. The Chicago Public Art Program provides the paintings, murals, sculptures, and exhibits in the corridors of both airports. O'Hare International Airport displays a replica of the fighter plane flown by Lieutenant Commander Edward H. O'Hare, the airport's namesake. Likewise, Midway contains an exhibit of the SBD Dauntless, a dive bomber plane recovered from Lake Michigan. Both airports also have restaurants that feature Chicago delicacies created by local chefs, but only O'Hare has the world's first airport aeroponic garden where foods for the airport restaurants are grown. Passengers waiting at both airports can relax and stretch in the Yoga Room. They can also visit the world's first aeroponic garden in an airport where foods for the airport restaurants are grown. While both airports are kid-friendly, O'Hare provides a special interactive children's area. The "Kids on the Fly Exhibit" allows children to play in a model airplane, helicopter, and control center. With the additions of the aeroponic garden and the children's play area, O'Hare offers a unique airport experience

What is the overall structure of this text?

Cause and effect
Chronological order
Compare and contrast
Problem and solution

part 1: the half-life of the element is 22 years.

part 2: it will take 132.02 year for the sample to decay from 308.0 g to 4.8125 g.

explanation:

part 1: there are two ways to determine the half life time.

first way: the half life time can be determined directly from its definition as it is the time required for the sample to decay to its half concentration.

from the data the initial concentration was 45.0 g and decayed to its half value (22.5 g) in 22.0 years.

second way: the radio active decay is considered first order reaction so we can use the laws of first order reactions.

k = (1/t) ln (a/a-x), where k is the rate constant of the reaction,

t is the time of the reaction

a is the initial concentration of the reactant

a-x is the remaining concentration at time (t)

a = 45.0 g the initial concentration at t = 0 year.

at t = 22 year, a-x = 22.5 g

then k = (1/22 year) ln (45.0 g/ 22.5 g) = 0.0315 year-1.

the half-life time (t1/2) = ln 2/ k = 0.693/ k =0.693/ 0.0315 = 22 years.

part 2:

using the same law k = (1/t) ln (a/a-x),

using the given data; a = 308.0 g and a-x = 4.8125 g and the calculated k from the part 1 (k = 0.0315 year-1)

t = (1/k) ln (a/a-x) = (1/0.0315) ln (308.0/ 4.8125) = 132.02 years

explanation:

the largest database of organic compounds lists about 10 million substances, which include compounds originating from living organisms and those synthesized by chemists. the number of potential organic compounds has been estimated at 1060—an astronomically high number. the existence of so many organic molecules is a consequence of the ability of carbon atoms to form up to four strong bonds to other carbon atoms, resulting in chains and rings of many different sizes, shapes, and complexities. the simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons. even though they are composed of only two types of atoms, there is a wide variety of hydrocarbons because they may consist of varying lengths of chains, branched chains, and rings of carbon atoms, or combinations of these structures. in addition, hydrocarbons may differ in the types of carbon-carbon bonds present in their molecules. many hydrocarbons are found in plants, animals, and their fossils; other hydrocarbons have been prepared in the laboratory. we use hydrocarbons every day, mainly as fuels, such as natural gas, acetylene, propane, butane, and the principal components of gasoline, diesel fuel, and heating oil. the familiar plastics polyethylene, polypropylene, and polystyrene are also hydrocarbons. we can distinguish several types of hydrocarbons by differences in the bonding between carbon atoms. this leads to differences in geometries and in the hybridization of the carbon orbitals.