period of periodic table definition chemistry

When an atom loses an electron it forms a cation and when it gains an electron it becomes an anion. Ions are formed when an atom loses or gains electrons.

There is a recurring pattern called the periodic law in their properties, in which elements in the same column (group) have similar properties. Ionic radius is the distance from the nucleus of an ion up to which it has an influence on its electron cloud. The number of shells in an atom of an element can be determined by noting the number of the period in which that element is found. It is organized in order of increasing atomic number. Not to miss out, element 102, Nobelium, No, is named in honor of Alfred Nobel, who set aside his vast fortune to establish Nobel Prizes. The periodic table is a tabular arrangement of the chemical elements. Mendeleev never received a Nobel Prize for his work, but element 101 was named Mendelevium, Md, after him. Arranged this way, elements in the same group (column) have similar chemical and physical properties, reflecting the periodic law. Each next element in a period has one more proton and is less metallic than its predecessor. All elements in a row have the same number of electron shells. For instance they discovered phosphorus when they isolated it from urine. A period on the periodic table is a row of chemical elements. Over time these gaps have gradually been filled in as scientists unearthed new elements. Atomic number increases as you move down a group or across a period. Periods are horizontal rows (across) the periodic table, while groups are vertical columns (down) the table. Not only did Mendeleev arrange the elements in the correct way, but he also had the foresight to leave gaps for undiscovered elements. Groups and periods are two ways of categorizing elements in the periodic table. At that time, he had only 50 elements to arrange. He wrote the properties of the elements on pieces of card and rearranged them until he realised that, by putting them in order of increasing atomic weight, certain properties of elements regularly occurred. Key groups include alkali metals, alkaline earth metals, halogens. The table is divided into metals, nonmetals, and metalloids, each with distinct properties. Elements in the same group share similar characteristics, like reactivity. Then in 1869, a Russian scientist called Dmitri Mendeleev produced one of the first practical periodic tables. The periodic table organizes elements into groups and periods based on their chemical and physical properties. Several other attempts were made to group elements together over the coming decades. The earliest attempt to classify the elements was in 1789, when Antoine Lavoisier grouped the elements based on their properties into gases, non-metals, metals and earths. The discovery of other elements followed regularly and soon it became necessary to arrange them in some sort of order. However, the first scientific discovery of an element occurred in 1649 when Hennig Brand discovered phosphorous. Copper has been used by humans for as much as 7000 years and elements such as gold, silver, tin, lead and mercury have been known for many thousands of years.

Period of periodic table definition chemistry