Questions

Fear of places and situations that might cause panic, helplessness or embarrassment is called Agoraphobia. 

Fear of crossing road causes some panic in them and comes under Agoraphobia.

Jean Piaget was a cognitive psychologist who identified four stages of development: the sensorimotor stage from birth to 2 years, the preoperational stage from age 2 to age 7, the concrete operational stage from age 7 to 11, and the formal operational stage from age 11 to adult. He identified milestones that occur at each stage.

According to Piaget, the main task of the sensorimotor stage is for the child to learn the concept of object permanence, use senses and motor skills to understand the world.

All chemistry is based on sharing electrons. A chemical bond forms when two atoms transfer or share outer electrons to complete their outer shells.

A metalloid is an element with properties between metals and non metals or the mix of both.

The six metalloids are arsenic, silicon, germanium, boron, antimony and tellurium.

Hence, silicon is the only metalloid in the given list.

Size of the primary memory of a PC ranges between 256 KB to 640 KB.