Chemical fertilizers stimulate plant growth; but if the concentration is too high, they may damage roots. What precautions concerning chemical fertilizers must a gardener take?

Amniotes vertebrates are generally classified into three orders: Reptilian, Ayes (birds), and Mammalian. Of the following, which group of three animals contains one member of each order?

As temperature rises, solids generally become more soluble in water, but gases become less soluble. If a soft drink contains high concentrations of sugar and carbon dioxide, which of the following may be expected to happen if it is cooled down? A) Sugar may precipitate out. B) Gas bubbles may form and produce foam. C) Water may evaporate rapidly.

Ions are electrically charged particles that are formed when certain compounds are dissolved in water. These solutions will conduct electricity. The Swedish scientist Svante Arrhenius coined the term ion (which means wanderer) to explain why solutions of electrolytes will conduct an electric current. When an electrolyte forms into a solution, it dissolves or dissociates into ions, a process called ionization. If a substance does not ionize, it will not conduct an electric current. Electrolytes include most acids, bases, and salts. Some conductors include hydrogen and sodium chloride, copper sulfate, and potassium nitrate. Substances that are not electrolytes include distilled water, sugar water, and most organic compounds.

Which of the following is a nonelectrolyte?

Scientists believe that the universe is expanding because of which of the following indicators?

Humidity is the amount of water vapor in the air at a given time. At warm temperatures, air can hold more moisture than it can at cold temperatures. Relative humidity is the amount of vapor the air is holding expressed as a percentage of the amount the air is capable of holding. For example, at 86 degrees Fahrenheit, air can hold a maximum of 30.4 grams of water per cubic meter. If the air at the same temperature is holding only 15.2 grams of water, the relative humidity is 50 percent. At the point at which the air becomes saturated (exceeds the level of water vapor it can hold), it releases water vapor in the form of dew or condensation. If the air at 75 degree’ holding the maximum amount of moisture that it can, and the temperature suddenly drops to 60 degrees, what is likely to be the result?

The Smiths have four children, all girls. Their fifth child is a boy. Why did this change occur?

Air is composed of nitrogen, oxygen, argon, carbon dioxide, and other gasses. How may air be best described?

Table salt – sodium chloride, one of the most common substances occurring in nature – is best classified as which of the following?

The earth ______ on its axis from west to east.