Connection Among the Location in the Table, the Atomic Number, and Mass

Because some elements have similar properties as others, they were grouped together in an arrangement called the periodic table of the elements. A modern periodic table is shown in the first figure.

The periodic table of the elements is a chart of all the elements from which all matter in the universe is made. We'll explain it a bit more in a minute. But first we thought it might be a good idea to go back and review a few of the basic principles of chemistry.

Chemistry is the study of matter and how it behaves and changes. What's matter? Matter is the name scientists give to anything you can see, feel, touch or smell. Everything in the universe is made up of matter. A good definition for matter is anything that has mass and occupies space. 
Matter can exist in four states: solid, liquid, gas, and plasma. It can have physical properties like color or smell; it can have chemical properties like how well it reacts with oxygen. And it can undergo both physical and chemical changes. Matter is made up of elements. And elements are made up of atoms. An atom is the smallest part of an element that has all the properties of that element.