<span>In the periodic table, the elements are organized into groups based on putting together elements with similar properties. For instance, elements in each group have the same number of valence electrons, which makes them form similar bonds. Additionally, elements in the same similar characteristics, such as malleability and magnetism.</span>
Answer:Sources of lead emissions vary from one area to another. At the national level, major sources of lead in the air are ore and metals processing and piston-engine aircraft operating on leaded aviation fuel. Other sources are waste incinerators, utilities, and lead-acid battery manufacturers. The highest air concentrations of lead are usually found near lead smelters.
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