Periodic table

5. Elements in group 16.
7. Repulsion by inner core electrons to valence electrons.
8. Inventor of modern periodic table.
11. contains elements that have similar physical or chemical properties.
13. metals in group 3-12.
16. Positively charged species having smaller size than parent atom.
17. Species that contain same number of electrons but different nuclear charge.
18. a row of elements in the periodic table whose properties change gradually and predictably.
19. Elements are arranged in order of increasing atomic weights and represented in cylindrical table.

1. Attractive force by nucleus.
2. Property of nitrogen due to which it shows exception behavior with oxygen in regards of first ionization enthalpy.
3. Trend of electronegativity on moving from left to right in periodic table.
4. Another name for f-block elements.
6. Elements in group 15.
8. Classification of elements with similar properties in group of three elements.
9. Trend of Ionization enthalpy down the group.
10. gases or brittle solids at room temperature and poor conductors of heat and electricity.
12. They have highly negative value of electron gain enthalpy.
14. Tendency of atom to attract shared pair of electron toward itself in covalently bonded molecule.
15. Nature of oxide of metals.