Some metals are in a special group.
They are all shiny. Some are found in the ground. One is made in a lab. We use some in batteries. Can you find them?
Some metals belong to a special group.
There are four metals in this group. Manganese is found in the ground. It is very common. We use it to make batteries.
Rhenium is a very rare metal. Technetium is also very hard to find. Bohrium is different. It is made by people in a lab. These metals can look silvery or gray. They are all very shiny. It is fun to learn about them!
Group 7 is a family of metals in the periodic table.
This group includes manganese, technetium, rhenium, and bohrium. These are all transition metals. This means they belong to a large block of metals.
Each metal is different in nature. Manganese is quite common in the world. Rhenium is very rare. Technetium is also hard to find in small amounts. Bohrium is different because it is synthetic. This means people make it in a lab.
These metals often look silvery or gray. They can also look like shiny metal.
Manganese is very useful. One type, manganese(IV) oxide, is used to make dry-cell batteries. This includes the alkaline batteries we use every day.
Some metals in this group form special shapes. Technetium can form many kinds of shapes.
These shapes are called structures. These structures help scientists understand how the metals work. Rhenium can also be used as a catalyst. A catalyst helps speed up a chemical change. Many of these metals form oxides when they react with oxygen.
Group 7 is a special family of metals in the periodic table.
These elements are called transition metals. This means they live in a specific part of the table called the d-block. The group includes four different elements: manganese, technetium, rhenium, and bohrium. Scientists often call this the manganese group. This name comes from manganese because it is the lightest member. These metals are important because they show patterns in how their electrons are arranged. Their outer electron shells help decide how they act in chemical reactions.
These metals work in different ways when they react with other things. Many of them like to reach a state called an oxidation state of +7. This is a way of describing how they share electrons. As you move down the group, this +7 state becomes more stable. For example, manganese can form many different oxides. One type, manganese(IV) oxide, is a black or brown solid. It is found in nature as a mineral called pyrolusite.
Manganese can also form light pink solids when it is in a +2 state. Other metals like rhenium can also form different states like +3 or +4.
History shows us how we discovered these metals. Manganese is a common element found in nature. Technetium was first studied in a different way in 1949. Scientists produced technetium(IV) oxide by using a process called electrolysis. This involves using electricity to change a liquid solution. Rhenium is much rarer than manganese.
Rhenium(VII) oxide is used as a raw material for other rhenium compounds. It is often made by heating rhenium in the air. Bohrium is very different from the others. It is a synthetic element, which means people must make it in a lab.
There are many interesting facts about their physical properties. Manganese is a silvery metal with a melting point of 1246 °C. Technetium is a silvery-gray metal that melts at 2157 °C. Rhenium is also silvery-gray and has a much higher melting point of 3186 °C.
Rhenium is also very heavy, with a density of 21.02 g/cm³. Bohrium is expected to have a density between 26 and 27 g/cm³, but it has not been measured yet. Most of these metals form a specific crystal shape called hexagonal close packed. However, manganese is different and uses a body centered cubic structure.
You can see these metals working in things you use every day. Manganese(IV) oxide is a key part of dry-cell batteries.
This includes the alkaline batteries used in many small devices. Rhenium can be used as a catalyst. A catalyst is something that helps a chemical reaction happen. Manganese is also used in the lighting industry and to make special glass. Even technetium has special uses in science.
These elements show how tiny particles make up our big world.
Group 7 is a specific family of elements located in the d-block of the periodic table.
Because they reside in this block, these elements are classified as transition metals. The group consists of four distinct elements: manganese (Mn), technetium (Tc), rhenium (Re), and bohrium (Bh). While the group is sometimes called the manganese group due to its lightest member, it lacks a unique trivial name. This is because it is part of the much larger category of transition metals. These elements are defined by patterns in their electron configurations. Specifically, the arrangement of their outermost shells dictates how they behave during chemical reactions.
The chemical behavior of Group 7 is largely defined by their oxidation states. An oxidation state describes the charge an atom takes on when it forms compounds. Most members of this group readily reach a +7 oxidation state. This trend becomes more stable as you move down the group from manganese to bohrium. However, the group is less consistent in this pattern than the groups preceding it. For example, technetium can maintain a stable +4 state. Rhenium also shows stability in both +4 and +3 states. Bohrium is expected to exhibit these lower states as well. In high oxidation states, these metals often form oxyanions, which are ions containing oxygen.
Each element in Group 7 has a different origin and abundance in our world. Manganese is a fairly common element found in nature. In contrast, rhenium is considered a rare element. Technetium is even more elusive, occurring only in trace quantities in nature. Bohrium is entirely different because it is a synthetic element. This means it does not occur naturally and must be created by scientists in a laboratory. The physical structures of these elements also vary. Most of the group crystallizes in a hexagonal close packed (hcp) structure. Manganese is the exception, as it uses a body centered cubic (bcc) structure. Bohrium is predicted to follow the hcp pattern used by its neighbors.
The physical properties of these metals change significantly as you move down the periodic table. Manganese is a silvery metal with a melting point of 1519 K (1246 °C). As you move to technetium, the melting point rises to 2430 K (2157 °C). Rhenium has an even higher melting point of 3459 K (3186 °C). The density of these elements also increases dramatically. Manganese has a density of 7.21 g/cm³, while rhenium reaches 21.02 g/cm³.
The density of bohrium is not yet measured, but it is predicted to be between 26 and 27 g/cm³. These changes reflect the addition of a filled f-shell into the atomic core as the elements get heavier.
Manganese is known for forming a wide variety of oxides. Manganese(II) oxide creates green crystals and can be nonstoichiometric, meaning its composition varies slightly.
Manganese(IV) oxide is a blackish or brown solid that occurs naturally as the mineral pyrolusite. This mineral is the primary ore of manganese. Manganese(VII) oxide is a dark green crystal that decomposes when it touches water. Other forms include manganese(III) oxide, which is unique because it does not adopt the common corundum structure. Research has even focused on creating very tiny manganese(III,IV) oxide nanorods.
Technetium and rhenium also form important compounds with oxygen and halogens. Technetium(IV) oxide was first produced in 1949 through electrolysis.
This process uses electricity to drive a chemical change in a liquid solution. Technetium(VII) oxide is a rare example of a molecular binary metal oxide. Rhenium(IV) oxide is a gray to black solid used as a laboratory reagent. It can act as a catalyst, which is a substance that speeds up a chemical reaction.
Rhenium(VII) oxide is the essential raw material for making all other rhenium compounds. It is obtained by roasting the host ore.
These elements have practical uses in modern technology and science. Manganese(IV) oxide is a critical component in dry-cell batteries, such as alkaline and zinc-carbon batteries.
Manganese is also used in the lighting industry and to produce special types of glass. Technetium is used in scientific studies involving complex structures.
Even the complex halides of technetium, which form clusters and chains, help scientists understand atomic bonding. The study of Group 7 helps us understand the broader systems of the d-block and the behavior of heavy transition metals.
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