Distinguish Isotopes from Isobar.

What are isotones? Give one example.

The atomic number of an element is 9. It has 10 neutrons. Find the element from the periodic table. What will be its mass number?

An atom of an element has no electron, will that atom have any mass or not? Can an atom exist without electron? If so then give example.

Find what is common salt? Name the elements present in it? Write the formula of common salt. What are the atomic number and the mass number of the elements? Write the ions in the compound.

Draw the structure of an atom and explain the position of the sub-atomic particles.

The atomic number and the mass number of an element is 26 and 56 respectively. Calculate the number of electrons, protons and neutrons in its atom. Draw the structure.

What are nucleons? Why are they called so? Write the properties of the nucleons.

Define valency? What is the valency of the element with atomic number 8? What is the compound format by this element with hydrogen?

Explain the following terms.
(i) Proton,
(ii) Electron,
(iii) Neutron.