Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the north and south poles of atoms point in all different directions, so overall the material is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets.  Rob got a compass as a present for his birthday. The magnet in the compass made him very interested in how magnets work. To understand magnets better he categorized objects in two groups, group A and group B. In group A all objects were magnetic, but in group B none of the objects was magnetic.  Which groups atom's poles would align in more orderly fashion, group A or group B?
Ans: group A

Cholesterol has been implicated in heart disease for decades. Atherosclerosis is a disorder of the arteries in which cholesterol and other materials are deposited on the interior of the arterial wall. These deposits lead to the formation of plaques that can restrict or even block the flow of blood through these blood vessels (see Figure below ). A decrease in the flow of blood can lead to high blood pressure and a lowered oxygen supply to the heart muscle. A complete blockage of blood flow to parts of the heart (a heart attack) can cause significant damage due to oxygen deprivation, in some cases leading to death.  Two brothers went to the doctor's office for an appointment. The doctor discovered that Tim had very high levels of cholesterol, while Jim had normal levels.  Which brother experiences a lowered oxygen supply to the heart muscle?
Ans: Tim

Pollutants also affect the atmosphere through their contribution to global warming. Global warming is an increase in the Earth’s temperature. It is thought to be caused mostly by the increase of greenhouse gases like carbon dioxide. Greenhouse gases can be released by factories that burn fossil fuels. Over the past 20 years, burning fossil fuels has produced about three-quarters of the carbon dioxide from human activity. The rest of the carbon dioxide in the atmosphere is there because of deforestation, or cutting down trees ( Figure below ). Trees absorb carbon dioxide during cellular respiration, so when trees are cut down, they cannot remove carbon dioxide from the air.  Long island was full of people and they used all their natural resources and burned fossil fuels while Snail island protected the environment and had fewer people living there.  Which island contributed more to global warming?
Ans: Long

In nature, when the population size is small, there is usually plenty of food and other resources for each individual. When there is plenty of food and other resources, organisms can easily reproduce, so the birth rate is high. As the population increases, the food supply, or the supply of another necessary resource, may decrease. When necessary resources, such as food, decrease, some individuals will die. Overall, the population cannot reproduce at the same rate, so the birth rates drop. This will cause the population growth rate to decrease.  Bill studied two herds of deer for a year. He was in love with nature. He observed the large herd named Alpha inhabited an area with fewer resources. Herd Beta was a smaller one, and they grazed on an abundance of plants.  Which herd had other resources available for each individual?
