assignments --> Unit 3 part 4


change Metals

teams with metalloids


Characteristics of team 17 the the routine table.

You are watching: How many valence electrons does halogens have

· identify halogens.

· explain physical and also chemical properties of halogens.

· list some offers of halogens.


You’ve most likely seen halogen lights choose the people pictured here. You may even have halogen lights in your home. If you do, friend may have actually noticed the they gain really hot and give turn off a lot of light for their size. A halogen irradiate differs from a regular incandescent light pear in having a tiny amount the halogen gas inside the bulb. The gas combine chemically with the steel in the filament, and this expand the life of the filament. It permits the lamp to obtain hotter and also give off an ext light 보다 a consistent incandescent light without burning the end quickly. What is halogen gas, and also whichelementsare halogens? In this article, you’ll uncover out.  

Meet the Halogens

Halogensare highly reactive nonmetallicelementsin group 17 that the routine table. Together you have the right to see in the routine table displayed in theFigurebelow, the halogens incorporate theelementsfluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). Every one of them are relatively common on planet except because that astatine. Astatine is radioactive and rapidly decays to other, an ext stable elements. As a result, it is one of the the very least common elements on Earth.


Q:Based ~ above their position in the routine table native theFigureabove, how many valenceelectronsdo you think halogens have?

A:The variety of valenceelectronsstarts at one for aspects in group 1. The then increases by one from left come right across each period (row) the the regular table for groups 1–2 and 13–18. Therefore, halogens have actually seven valence electrons.

Chemical nature of Halogens

The halogens are amongst the most reactive of all elements, back reactivity decreases from the peak to the bottom the the halogen group. Due to the fact that all halogens have actually seven valenceelectrons, they are “eager” to get one an ext electron. Act so provides them a full outerenergy level, i m sorry is the many stable plan of electrons. Halogens often integrate with alkalimetalsin group 1 that the routine table. Alkali metals have just one valence electron, which they space equally “eager” come donate. Reactions involving halogens, especially halogens near the top of the group, might be explosive. You can see some examples in the video clip at the URL below. (Warning:Don’t shot any of these reactions in ~ home!)


Physical nature of Halogens

The halogen group is quite diverse. The includes facets that occur in 3 differentstates of matterat roomtemperature. Fluorine and chlorine aregases, bromine is a liquid, and iodine and astatine aresolids. Halogens additionally varyincolor, together you have the right to see in theFigurebelow. Fluorine and chlorine space green, bromine is red, and also iodine and also astatine are practically black. Like various other nonmetals, halogens can not conduct electrical energy orheat. Compared with most other elements, halogens have relatively lowmeltingandboilingpoints. You deserve to watch a rap demonstration the the melting and also boiling clues of halogens at this URL:http://www.youtube.com/watch?v=yP0U5rGWqdg.


Uses that Halogens

Most halogens have actually a selection of crucial uses. A couple of are defined in theTablebelow.

A few Uses the Halogens




Fluorine helps stop tooth decay, so that is included to toothpaste as the compound sodium fluoride. You can learn exactly how it protects teeth at this URL:http://www.animated-teeth.com/tooth_decay/t4_tooth_decay_fluoride.htm.


Chlorine is the active ingredient in household bleach. It clears stains from clothes. That can likewise be supplied to disinfect countertops and also other surfaces.


Bromine is used to purifywaterin swim pools and also hot tubs. It reacts through bacteria and other germs and renders castle harmless.


Iodine is included to alcohol and also used as an antiseptic. That reacts with germs ~ above cuts and wounds. Tiny amounts of iodine are additionally needed for good health. In the U.S., iodine is added to table salt to protect against iodine deficiencies. Walk the salt you usage contain iodine?

Q:Can girlfriend relate several of these uses of halogens come the properties of this elements?

A:The capability of halogens to kill germs and also bleach apparel relates come their extremely reactive nature.


· Halogens are very reactive nonmetal facets in group 17 the the routine table.

· Halogens includesolids,liquids, andgasesat roomtemperature, and they differ incolor.

· Halogens are among the many reactive of all elements. They have actually seven valence electrons, so they are an extremely “eager” to get one electron to have a complete outerenergy level.

· Halogens have a range of crucial uses, such as avoiding tooth decay and killing germs.

Explore More

TheTablebelowgives themeltingandboilingpoints that halogens. Create a graph v the data, and also then explain in native the trends that you check out in her graph.

MeltingandBoilingPoints the Halogens


Melting point (°C)

Boiling allude (°C)

















1. What room halogens?

2. Why room halogens very reactive?

3. Describe the physical properties that halogens.

4. Why is chlorine included to swim poolwater?

Transition Metals

Characteristics of teams 3 - 12 of the routine table.

· determine transitionmetals.

· list properties that transitionmetals.

· describe thelanthanides and actinides.


What do every one of the objects pictured above have in common? all of them room made totally or mostly of copper. Copper has actually an amazing selection of uses, including food preparation pots, plumbing pipes, roofing tiles, jewelry,musical instruments, and electric wires. Copper is a good choice because that these and many other objects since of that is properties. It can be developed into wires and flat sheets, it’s a good conductor ofheatand electricity, it’s hard and also strong, and also it doesn’t corrode easily. In all these ways, copper is a typical change metal.

What are TransitionMetals?

Transition metalsare all theelementsin teams 3–12 that the regular table. In the periodic table pictured inFigurebelow, they are theelementsshaded yellow, pink, and also purple. The transition metals make up around 60 percent the all known elements. In enhancement to copper (Cu), fine known instances of shift metals include iron (Fe), zinc (Zn), silver (Ag), and also gold (Au) (Copper (Cu) is pictured in its miscellaneous applications in the opening image). You have the right to explore details transition steels with the interactive regular table in ~ this URL:http://www.ptable.com/.


Q:Transition metals have been called the most common of all metals. What do you think this means?

A:Unlike some other metals, shift metals have actually the properties that specify the steels class. They are wonderful conductors that electricity, because that example, and they also have luster, malleability, and also ductility. You can read an ext about these properties of shift metals below.

Properties of transition Metals

Transition metals are exceptional conductors ofheatas well together electricity. They are malleable, which method they can be shaped into sheets, and also ductile, which means they can be shaped right into wires. They have highmeltingandboilingpoints, and also all aresolidsat roomtemperature, except for mercury (Hg), which is a liquid. Change metals are additionally high in density and an extremely hard. Many of them are white or silvery incolor, and they are normally lustrous, or shiny. Thecompoundsthat transition metals form with otherelementsare often an extremely colorful. You can see several examples in theFigurebelow.


Some nature of transition metals collection them personal from various other metals. Compared with the alkali metals in team 1 and the alkaline earth metals in group 2, the shift metals room much much less reactive. They don’t react quickly withwateror oxygen, which explains why lock resistcorrosion.

Other properties of the transition metals room unique. They space the only elements that might useelectronsin the next to highest—as well together the highest—energy levelas valence electrons. Valence electrons are the electron that kind bonds with other elements incompoundsand that normally determine the nature of elements. Transition metals are unusual in having very comparable properties even with different numbers of valence electrons. The change metals also include the only facets that develop a magnetic field. 3 of them have this property: steel (Fe), cobalt (Co), and also nickel (Ni).

Q:How is the variety of valenceelectronstypically pertained to the properties of elements?

A:The number of valenceelectronsusually determines how reactive aspects are and the ways in i beg your pardon they reaction with other elements.

Those elements Down Under

Transition metals include the elements that are most often placed listed below the routine table (the pink- and purple-shaded facets in theFigureabove). Those that follow lanthanum (La) are called lanthanides. They are all relatively reactive for change metals. Those that follow actinium (Ac) are called actinides. They space all radioactive. This means that they are unstable, therefore they degeneration into different, much more stable elements. Numerous of the actinides execute not occur in nature but are made inlaboratories.


· shift metals space all the elements in teams 3–12 of the regular table. More than half of all elements are shift metals.

· change metals are common metals, v properties such as a superior capacity to conduct electrical energy andheat. They likewise have the metallic nature of luster, malleability, and also ductility. In addition, transition metals have actually highmeltingandboilingpoints and high density.

· Thelanthanides and actinidesare the change metals that room usually placed below the main part of the regular table. Lanthanides are reasonably reactive for shift metals, and also actinides room radioactive.

Explore More

At the complying with URL, click on any two that the change metals and read about their properties,atomic structure, discovery, and also uses. Then create a paragraph comparing and contrasting the two elements.



1. What are shift metals?

2. Explain properties of shift metals.

3. How do transition metals differ from metals in teams 1 and 2? exactly how are they different from all various other elements?

4. Recognize thelanthanides and actinides.

Groups with Metalloids

Characteristics of groups 13 - 16 that the regular table.

· Identifyelementsin teams 13–16 the the regular table.

· list properties the a metalloid from every of these groups.


This photo represents a famous old Egyptian called Tutankhamen. Do you view his hefty eyeliner? Most likely the eyeliner was made the a mineral comprise antimony. This metalloid was commonly used for makeup by Egyptians in between four and also five thousand year ago. Today we know that antimony is toxic, return Tutankhamen probably didn’t know that. Antimony is discovered in group 15 of the periodic table. Group 15 is one of four groups of the routine table the containmetalloids.  

Groups 13–16

Groups 13–16 that the periodic table (orange in theFigurebelow) space the only groups that containelementsclassified asmetalloids. Unlike other teams of the regular table, i m sorry contain aspects in just one class, groups 13–16 contain facets in at least two various classes. In addition to metalloids, they also containmetals, nonmetals, or both. Groups 13–16 fall between the shift metals (in teams 3–12) and also the nonmetals calledhalogens(in team 17).


What AreMetalloids?

Metalloidsare the smallest course ofelements, containing simply six members: boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te). Metalloids have actually some properties ofmetals(elements that can conduct electricity) and also some nature of nonmetals (elements the cannot conduct electricity). For example, most metalloids deserve to conduct electricity, but not and metals. Metalloids additionally tend to be shiny choose metals, but brittle prefer nonmetals. Chemically, metalloids might behave like metals or nonmetals, depending on their variety of valenceelectrons. You have the right to learn an ext about particular metalloids by clicking on the element symbols in the periodic table at this URL:http://www.chemicool.com/.

Q:Why go the chemical habits of an facet depend ~ above its variety of valenceelectrons?

A:Valenceelectronsare the electron in one atom’s outerenergy levelthat may be involved inchemical reactionswith otheratoms.

See more: 2/3 Divided By 1/2 - Fraction Calculator

Group 13: Boron Group

Group 13 the the regular table is additionally called the boron group due to the fact that boron (B) is the an initial element in ~ the top of the group (seeFigurebelow). Boron is likewise the only metalloid in this group. The various other four elements in the group—aluminum (Al), gallium (Ga), indium (In), and thallium (Tl)—are allmetals. Team 13 aspects have three valence electrons and also are fairly reactive. Every one of them aresolidsat roomtemperature.