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the main groups are numbered from 1 to 7 going from left to right, and the last group on the right is Group 0. the block in between Group 2 and Group 3 is where the transition metals...
Group 1 - the alkali metals - Edexcel. The group 1 elements are all soft, reactive metals with low melting points. They react with water to produce an alkaline metal hydroxide solution and...
Apr 12, 2023 · The periodic table achieved its modern form through the work of the German chemist Julius Lothar Meyer (1830–1895) and the Russian chemist Dimitri Mendeleev (1834–1907), both of whom focused on the relationships between atomic mass and various physical and chemical properties.
- Alkali Metals
- Alkaline Earth Metals
- Transition Metals
- Post-Transition Metals
- Metalloids
- Nonmetals
- Halogens
- Noble Gases
- Lanthanides
- Actinides
The alkali metals are all elements of Group I except hydrogen. These elements have one valence electron. They are highly reactive and can burst into flames when exposed to air. This is why alkali metals combine with other elements in compounds. They react with water quickly and must be stored in oil. Franciumis the most reactive alkali metal, locat...
The alkaline earth metals are located in Group 2 of the periodic table, from beryllium (Be) to radium (Ra). They have two electrons in their outermost shell and are the second most reactive after alkali metals. They are a strong reducing agent, meaning they can donate electrons quickly. They are also good conductors of heat and electricity. Physica...
The transition metals lie from Group 3 to Group 12. They have more than one oxidation state, meaning they can have many oxidation numbers. They have low ionization energy and high conductivity. Aside, they have high melting and boiling points. They can be malleable and shiny.
The post-transition metals are located in between transition metals and the metalloids. They span from Groups 13 to 16. They have some characteristics of transition metals but are soft and conduct more poorly than transition metals. Their melting points are lower than transition metals.
The metalloids display properties in between metals and nonmetals. Only six such elements exist, of which three (B, Si, and Ge) are semiconductors. They lie between Groups 13 and 16. Metalloids are not as good conductors of electricity as metals, nor are they as ductile as metals. They are brittle and can break easily.
Nonmetals are on the top right of metalloids, spanning Groups 13 and 16. They have high electronegativity and ionization energy and are poor conductors of heat and electricity. They exist as gases like oxygen or solids like carbon. Although it is in Group 1, hydrogen is considered a nonmetal.
The halogens lie in Group 17. They are highly electronegative and reactive, requiring one electron to complete their outermost shell. Hence, they typically exhibit a -1 oxidation state. They form salts with metals.
The elements in Group 18 are called noble gases. They have complete outermost shells, resulting in stable electron configurations. Hence, they are the least reactive group on the periodic table, giving them nomenclature inert gases. They have low melting and boiling points and are colorless and odorless.
Lanthanides are a part of the sixth row and lie within Group 3 of the periodic table. The name lanthanide comes from the first element of that row – lanthanum. They are a family of rare earth metals with one valence electron in the 5d shell. They are highly reactive and behave like strong reducing agents in chemical reactions. Aside, they are soft ...
Actinides are located in the seventh row and within Group 3. Their name comes from actinium, the first element of that row. They are another family of rare earth metals that are highly reactive. They also have high electropositivity and are radioactive. Aside, these elements are allotropic, paramagnetic, and pyromorphic. Physically, they are very s...
Dalton (1803) arranged known elements in order of atomic weights. Newlands (1865) noticed that every eighth element, in order of atomic mass, repeated similar properties. Mendeleev swapped the order of atomic weights in order to fit elements better into groups of similar properties.
Questions and model answers on 1.2 The Periodic Table for the AQA GCSE Chemistry: Combined Science syllabus, written by the Chemistry experts at Save My Exams.
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The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows (" periods ") and columns (" groups "). It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order ...
