Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major formsâ white phosphorus and red phosphorus âbut due to its high reactivity, phosphorus is never found as a free element on Earth. Instead phosphorus-containing minerals are almost always present in their maximally oxidised state, as inorganic phosphate rocks.
Ages & Stages â Preschool Children. Three and four-year-old children are often called preschoolers. Preschool children want to touch, taste, smell, hear, and test things for themselves. They are eager to learn. They learn by experiencing and by doing. Preschoolers learn from their play.
Free Preschool Curriculum. Preschool is a time of rapid growth and development. While the preschool curriculum is designed keeping in mind the physical and intellectual developmental characteristics of 2 â 5 year olds, there are certain milestones that most preschoolers should achieve before they begin kindergarten.