1What is an element? Which statement about elements is correct, and why?
2What is an atom? Draw and describe the structure of an atom so that the electron, proton and nucleus can be identified.
3What are subatomic particles? Which particles come under them, and where are they found?
4Give the reason: a neutral atom carries no charge.
5Write the names and symbols of the elements with atomic numbers 7, 13 and 17.
6Why is the symbol of potassium K rather than P?
7An element has 18 neutrons. Can you name it from that alone? Explain.
8An atom has 10 protons and 10 neutrons. Name it, give its symbol, and draw its structure.
9Why do the electrons not appear in the atomic weight?
10Why is the number of protons, rather than anything else, taken as the identity of an element?