Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
--------
Question: According to the United States Department of Labors Bureau of Labor Statistics, there were approximately 210,900 physical therapists employed in the United States in 2014, earning an average $84,020 annually in 2015, or $40.40 per hour, with 34% growth in employment projected by the year 2024. The Bureau of Labor Statistics also reports that there were approximately 128,700 Physical Therapist Assistants and Aides employed in the United States in 2014, earning an average $42,980 annually, or $20.66 per hour, with 40% growth in employment projected by the year 2024. To meet their needs, many healthcare and physical therapy facilities hire "travel physical therapists", who work temporary assignments between 8 and 26 weeks for much higher wages; about $113,500 a year. Bureau of Labor Statistics data on PTAs and Techs can be difficult to decipher, due to their tendency to report data on these job fields collectively rather than separately. O-Net reports that in 2015, PTAs in the United States earned a median wage of $55,170 annually or $26.52 hourly, and that Aides/Techs earned a median wage of $25,120 annually or $12.08 hourly in 2015. The American Physical Therapy Association reports vacancy rates for physical therapists as 11.2% in outpatient private practice, 10% in acute care settings, and 12.1% in skilled nursing facilities. The APTA also reports turnover rates for physical therapists as 10.7% in outpatient private practice, 11.9% in acute care settings, 27.6% in skilled nursing facilities.

Answer: What group has the highest percentage of vacancy for Physical Therapist Assistants?


Question: Does everyone want a challenging job? In spite of all the attention focused by the media, academicians, and social scientists on human potential and the needs of individuals, there is no evidence to support that the vast majority of workers want challenging jobs. Some individuals prefer highly complex and challenging jobs; others develop in simple, routine work. The individual-difference variable that seems to gain the greatest support for explaining who prefers a challenging job and who doesn't is the strength of an individual's needs for personal growth and self-direction at work. Individuals with these higher-order growth needs are more responsive for challenging work. What percentage of ordinary workers actually desire higher-order need satisfactions and will respond positively to challenging jobs? No current data is available, but a study from the 1970s estimated the figure at about 15%. Even after adjusting for changing work attitudes and the growth in white-collar jobs, it seems unlikely that the number today exceeds 40%. The strongest voice advocating challenging jobs has not been workers--it's been professors, social science researchers, and media people. Professors, researchers, and journalists undoubtedly made their career choices, to some degree, because they wanted jobs that gave them autonomy, recognition and challenge. That, of course, is their choice. But for them, to force their needs onto the workforce in general is presumptuous . Not every employee is looking for a challenging job. Many workers meet their higher-order need off the job. There are 168 hours in every individual's week. Work rarely consumes more than 30% of this time. That leaves considerable opportunities, even for individuals with strong growth needs, to find higher-order need satisfaction outside the workplace. So don't feel you have a responsibility to create challenging jobs for all your employees. For many people, work is something that will never excite or challenge them. And they don't expect to find their growth opportunities at work. Work is merely something they have to do to pay their bills. They can find challenges outside of work on the golf course, fishing, at their local pub, with their friends in social clubs, with their family, and the like.

Answer: What makes people choose challenging jobs?


Question: To understand minerals, we must first understand matter. Matter is the substance that physical objects are made of. The basic unit of matter is an atom. At the center of an atom is its nucleus. Protons are positively charged particles in the nucleus. Also in the nucleus are neutrons with no electrical charge. Orbiting the nucleus are tiny electrons. Electrons are negatively charged. An atom with the same number of protons and electrons is electrically neutral. If the atom has more or less electrons to protons it is called an ion. An ion will have positive charge if it has more protons than electrons. It will have negative charge if it has more electrons than protons. An atom is the smallest unit of a chemical element. That is, an atom has all the properties of that element. All atoms of the same element have the same number of protons. A molecule is the smallest unit of a chemical compound. A compound is a substance made of two or more elements. The elements in a chemical compound are always present in a certain ratio. Water is probably one of the simplest compounds that you know. A water molecule is made of two hydrogen atoms and one oxygen atom (Figure 3.2). All water molecules have the same ratio: two hydrogen atoms to one oxygen atom. A mineral is a solid material that forms by a natural process. A mineral can be made of an element or a compound. It has a specific chemical composition that is different from other minerals. One minerals physical properties differ from others. These properties include crystal structure, hardness, density and color. Each is made of different elements. Each has different physical properties. For example, silver is a soft, shiny metal. Salt is a white, cube- shaped crystal. Diamond is an extremely hard, translucent crystal. Minerals are made by natural processes. The processes that make minerals happen in or on the Earth. For example, when hot lava cools, mineral crystals form. Minerals also precipitate from water. Some minerals grow when rocks are exposed to high pressures and temperatures. Could something like a mineral be made by a process that was not natural? People make gemstones in a laboratory. Synthetic diamond is a common one. But that stone is not a mineral. It was not formed by a natural process. A mineral is an inorganic substance. It was not made by living organisms. Organic substances contain carbon. Some organic substances are proteins, carbohydrates, and oils. Everything else is inorganic. In a few cases, living organisms make inorganic materials. The calcium carbonate shells made by marine animals are inorganic. All minerals have a definite chemical makeup. A few minerals are made of only one kind of element. Silver is a mineral made only of silver atoms. Diamond and graphite are both made only of the element carbon. Minerals that are not pure elements are made of chemical compounds. For example, the mineral quartz is made of the compound silicon dioxide, or SiO2 . This compound has one atom of the element silicon for every two atoms of the element oxygen. Each mineral has its own unique chemical formula. For example, the mineral hematite has two iron atoms for every three oxygen atoms. The mineral magnetite has three iron atoms for every four oxygen atoms. Many minerals have very complex chemical formulas that include several elements. However, even in more complicated compounds, the elements occur in definite ratios. Minerals must be solid. For example, ice and water have the same chemical composition. Ice is a solid, so it is a mineral. Water is a liquid, so it is not a mineral. Some solids are not crystals. Glass, or the rock obsidian, are solid but not crystals. In a crystal, the atoms are arranged in a pattern. This pattern is regular and it repeats. Figure 3.3 shows how the atoms are arranged in halite (table salt). Halite contains atoms of sodium and chlorine in a pattern. Notice that the pattern goes in all three dimensions. The pattern of atoms in all halite is the same. Think about all of the grains of salt that are

Answer:
smallest possible particle of a chemical compound