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.
For information on parenting and child development of preschool children (early childhood aged 3 to 7, please visit our Early Childhood Parenting and Child Development topic center. For information on parenting and child development of middle childhood children (ages 8 to 11), please visit our Middle Childhood Parenting and Development center. For information on parenting adolescents (ages 12-24), please visit our Child Development Theory: Adolescence topic center and Parenting and Child Development Theory: Adolescence topic center. When babies arrive in the world, they are tiny, helpless people who depend entirely on adults to take care of all their needs and wants.