differentiate between the thinking patterns of a 3-year-old preschooler and a 9-year-old student, according to Piaget's theory of cognitive development.

On the basis of Piaget's theory of cognitive development, a child undergoes four different stages of cognitive development to gain complete intellect from childhood to adulthood.

According to Piaget, a 3-year-old preschooler would be under the 'pre-operational' stage of cognitive development that ranges from the age of 2 to 7 years. During this stage, the child displays intelligence through the use of symbols, language use matures, development of memory and imagination takes place and thinking is done in an ego-centric, non-logical, and non-reversible manner.

While a child of 9-years-old is under the concrete operational stage which ranges from 7 to 11 years of age. At this stage, the child demonstrates intelligence through logical and systematic manipulation of symbols associated with concrete objects and development of operational thinking begins. The child becomes more practical and realistic.

according to hess's theory, when the magma cooled, it would expand and push the tectonic plates apart. it would push the north and south america plates to the west and eurasia and africa ones to the east. the atlantic ocean would get wider but the coastlines of the masses would stay the same.

harry hammond hess was a geologist and a united states navy officer in the second world war. he is considered to be one of the founding fathers of the theory of plate tectonics. he is known for his theories on sea floor spreading, stating that the movement of the continents was the result of see floor spreading. the continents are attached to the plates and do not move separately. the plates themselves shift and change shape, carrying the continents along.