Periodic Table summary
The periodic table is organized in many different sections and rows.
One way it is arranges is by atomic number. It starts at one and increases horizontally till one hundred-eighteen. The atomic number of an element is its number of protons that the element has. In atoms the number of protons and electrons are the same so it’s a neutral charge. When there are more protons than electrons or the other way around it is no longer called an atom. Its called an ion because its either positively or negatively charged. The ion charges are on the top right of the element.
Its also organized horizontally from smallest to largest atomic mass. Atomic mass is the mass of the atom.
The periodic table is split into three main sections. Metals, Nonmetals, and metalloids.
Metals tend to lose electrons making them positive ions. Nonmetals tend to gain electrons making them negative ions.
Metals are on the left side of the staircase looking line, nonmetals are on the right side, and metalloids, which are a mix of metals and nonmetals, and have similar properties to both are right along the stair case line. Those 3 sections are broken up into families and periods.
A family in the periodic table is a vertical column. The columns are numbered 1-18. It is one of the ways a periodic table is organized. The elements in a family all have similar properties. Like the electrons and valance electrons for example. In families 1,2,3,15,16,17, and 18 elements in the same family have the same ion charge. For example in family 2, the ion charge is 2+, meaning there are two more protons than electrons, making the ion positive. In family #16 the ion charge is –2, meaning there are two more electrons than protons, making the ion negative. There are 4 important families in the periodic table, that are given special names. The noble gases, Halogens, Alkali metals, and alkaline earth metals. Noble gases are on the far right side of the table, and are very unreactive because they already have a full outer shell. They don’t need to gain or lose electrons like other metals and nonmetals do. Alkaline earth metals are less reactive than alkali metals but will burn in air if heated. They produce bright flames, and are used in fireworks. Halogens are the most reactive nonmetals. They need to gain electrons because they don’t have a full outer shell of valance electrons to start with. They are nonmetals and are beside noble gases on the periodic table. The alkali metals are the most reactive elements out of al the other metals. They react with oxygen and water, have low melting points below 200 degrees Celsius. They are also soft enough to be cut with a knife. They have only one valance electron.
A period is a horizontal row of elements. The elements in a period also have some similarities. The numbers go from 1-7, and the period number also equals the number of valance electrons for the elements in that row.
Valance electrons are the elections on the outer shell of an atom. If the outer shell of valance electrons isn’t full that means the atom wants to with gain or lose electrons to create an outer shell. The electrons will do what makes sense. For example if the atom has only one valance electron it would make the most sense to get rid of it to create a full outer shell, but if it has 7 it would make more sense to gain one electron instead. Metals tend to lose electrons so they become positively charged. Nonmetals tend to gain electrons to become negatively charged. When an atom either gains or loses electrons it is no longer neutral charged so it becomes an ion. The more electrons the atom has to gain or lose the more reactive that element is.
Bohr models picture:
Periodic Table coloured picture: