States of matter are the different forms we find elements, compounds and mixtures in the periodic table as solids liquids and gases.
Ionic compounds have a number of properties due to their bonding, they are brittle, non conductive as a solid and have high melting and boiling points.
Groups in the periodic table are the columns where elements with similar properties are found grouped together.
The Metalloids is the term given to the elements in the periodic table that exist between metals and non metals on the right hand side. These are elements that exhibit both properties of metals and non metals.
The Actinides also known as the actinoids are a set of elements in the final period of the periodic table from elements 89 to 103. They are a series of radioactive elements with similar properties.