assignments --> unit 3 part 3 --> hydrogen and also alkali metals

assignments --> unit 3 part 3 --> alkali planet metals

assignments --> unit 3 part 3 --> nobel gases

COMPUTERS - practice until 100%

NO computers - create questions and also answers to the evaluation questions

Hydrogen and also Alkali Metals

Characteristics of group 1 that the regular table.

You are watching: Atoms of the least reactive elements tend to have

· recognize theelementsin team 1 of the regular table.

· describe why team 1elementsare very reactive.

· List other properties the alkalimetals.


You more than likely think ofwateras a substance that deserve to put the end fires. But someelementsare so reactive the they burn in water. In fact, they practically explode in water. That’s what is continue in the photo above. About 3 pounds of salt were added to water, and the result was this explosive reaction. Why is salt such a reactive element? In this lesson you will uncover out.

The first Group

Sodium (Na) is an aspect in group 1 the the routine table that the elements. This team (column) of the table is displayed below. It consists of the nonmetal hydrogen (H) and also sixmetalsthat room calledalkali metals. Elements in the same team of the periodic table have the same variety of valenceelectrons. These are the electron in their outerenergy levelthat deserve to be involved in chemical reactions. Valence electrons determine many of the properties of one element, so aspects in the same team have similar properties. All the facets in team 1 have actually just one valence electron. This makes them really reactive.

Q:Why does having actually just one valence electron make group 1 elements very reactive?

A:With just one valence electron, group 1 elements are “eager” to shed that electron. Act so permits them to achieve a complete outerenergy leveland maximum stability.


Reactivity of team 1 Elements

Hydrogen is a an extremely reactive gas, and the alkalimetalsare even an ext reactive. In fact, they space the most reactive metals and, along with the aspects in group 17, are the most reactive of every elements. The reactivity that alkali metals increases from the top to the bottom that the group, therefore lithium (Li) is the the very least reactive alkali metal and francium (Fr) is the most reactive. Due to the fact that alkali steels are therefore reactive, they are found in nature only in combination with other elements. Castle often incorporate with team 17 elements, i beg your pardon are very “eager” to gain an electron. In ~ the URL below, you can watch a video clip that mirrors just just how reactive the alkali metals are.


Other properties of Alkali Metals

Besides being very reactive, alkali steels share a number of other properties.

· Alkali metals are allsolidsat roomtemperature.

· Alkali metals are low in density, and also some of lock float onwater.

· Alkali metals are relatively soft. Part are also soft sufficient to reduced with a knife, prefer the salt pictured in theFigurebelow.


A Closer Look

Although all group 1 elements share particular properties, such together being really reactive, they space not alike in every way. Three various group 1 elements are defined in more detail below (Figuresbelow,below, andbelow). An alert the means in i m sorry they differ from one another.


Hydrogen has the smallest, lightest atoms of all elements. Pure hydrogen is a colorless, odorless, tasteless gas that is nontoxic but highly flammable. Hydrogen gas exists mainly as diatomic (“two-atom”) molecule (H2), as presented in the chart on the right. Hydrogen is the most abundant element in the universe and the third most abundant facet on Earth, arising mainly in compounds such as water.

Q:Why do you think hydrogen gas usually exists together diatomic molecules?

A:Each hydrogen atom has just one electron. As soon as two hydrogenatomsbond together, lock share a pair ofelectrons. The common electrons fill their onlyenergy level, giving them the most stable plan of electrons.


Potassium is a soft, silvery metal that ignites explosively in water. It quickly loses the one valence electron to form positive potassium ions (K+), i beg your pardon are needed by all living cells. Potassium is so vital for plants the it is uncovered in virtually all fertilizers, prefer the one shown here. Potassium is abundant in Earth’s tardy in minerals such as feldspar.


Francium has one of the largest, heaviest atom of all elements. Its one valence electron is much removed native the nucleus, together you have the right to see in the atomic model on the right, so that is conveniently removed from the atom. Francium is radioactive and also quickly decays to kind other aspects such together radium. This is why francium is very rare in nature. Much less than an oz of francium is present on earth at any type of given time.

Q:Francium decays too quickly to formcompoundswith other elements. Which elements to you think it would bond through if that could?

A:With one valence electron, francium would certainly bond v a halogen element in team 17, which has seven valenceelectronsand demands one more to fill its outer power level. Aspects in team 17 include fluorine and chlorine.


· group 1 the the routine table consists of hydrogen and also the alkali metals.

· since they have just one valence electron, group 1 aspects are an extremely reactive. As a result, lock are discovered in nature only in mix with various other elements.

· Alkali steels are allsolidsat roomtemperature. They are relatively soft and low in density.

· from the peak to the bottom of group 1, the facets have heavier, much more reactiveatoms.

Explore More

At the complying with URL, click “Group 1 data and also graphs.” use the data in the team 1 table to fill in the blanks listed below with eitherincreasesordecreases.


From the optimal to the bottom of group 1, properties of the alkali metals readjust as follows:

1. Melting point __________.

2. Boiling allude __________.

3. Density __________.

4. Atom radius __________.

5. Number of electrons __________.


1. What are alkali metals?

2. Why is hydrogen, a nonmetal, placed in the same team as the alkali metals?

3. Explain why group 1 facets often formcompoundswith elements in group 17.

4. Compare and also contrast hydrogen and francium.

Alkaline planet Metals

Characteristics of group 2 that the periodic table.

· identify alkaline Earthmetals.

· list properties that alkaline Earthmetals.

· describe why alkaline Earthmetalsare an extremely reactive.


Sparklers like the one this girl is holding do festive additions to numerous celebrations. You might use them yourself. However watch the end if you do due to the fact that their flames room really hot! The shining white flames are produced when magnesium burns. Magnesium is a light- weight metal that burns at a really hightemperature. Other uses of magnesium incorporate flash photography, flares, and also fireworks. Magnesium is a steel in group 2 that the routine table, i m sorry you will certainly read around in this concept.  

The second Group

Barium (Ba) is one of sixelementsin team 2 that the routine table, i m sorry is shown below. Facets in this group are calledalkaline earth metals. These steels are silver or gray incolor. They are fairly soft and also low in density, although not as soft and also lightweight together alkali metals. You deserve to watch a brief video introduction come the alkaline planet metals in ~ this URL:http://www.youtube.com/watch?v=DFQPnHkQlZM.


Reactivity that Alkaline earth Metals

All alkaline earth metals have similar properties due to the fact that they all have actually two valenceelectrons. Castle readily give up their two valence electrons to attain a complete outerenergy level, i beg your pardon is the many stable plan of electrons. Together a result, they are an extremely reactive, return not quite as reactive as the alkali steels in group 1. Because that example, alkaline earth metals will react v coldwater, however not explosively together alkali metals do. Due to the fact that of their reactivity, alkaline planet metals never ever exist as puresubstancesin nature. Instead, lock are constantly found combined with otherelements.

The reactivity that alkaline earth metals increases from the optimal to the bottom the the group. That’s because theatomsget bigger indigenous the height to the bottom, therefore the valenceelectronsare farther from the nucleus. When valence electrons are farther from the nucleus, they space attracted much less strongly by the cell core and more easily eliminated from the atom. This provides the atom an ext reactive.

Q:Alkali metals have actually just one valence electron. Why room alkaline earth metals much less reactive than alkali metals?

A:It takes more energy to eliminate two valenceelectronsfrom one atom than one valence electron. This renders alkaline planet metals with their 2 valence electrons much less reactive 보다 alkali steels with your one valence electron.

Examples of Alkaline planet Metals

For a far better understanding of alkaline earth metals, let’s take it a closer look at 2 of them: calcium (Ca) and strontium (Sr). Calcium is a soft, gray, nontoxic alkaline planet metal. Return pure calcium doesn’t exist in nature, calciumcompoundsare very common in Earth’s crust and in seawater. Calcium is additionally the most abundant metal in the human being body, emerging as calcium link such as calcium phosphate and also calcium carbonate. These calcium compound are uncovered in bones and also make lock hard and strong. The skeleton of the average adult contains around a kilogram of calcium. Because calcium—like barium—absorbs x-rays, bones present up white in x-ray images. Calcium is vital component that a healthy human diet. An excellent food sources of calcium room pictured inFigurebelow.


Q:What health problems might result from a diet short in calcium?

A:Children who don’t get enough calcium while your bones are forming may build a deficiency condition called rickets, in which your bones space softer than normal and also become bent and also stunted. Adults that don’t get enough calcium may construct a condition called osteoporosis, in which the bones shed calcium and also become weak and also brittle. Civilization with osteoporosis space at high threat of bone fractures.

Strontium is a silver-colored alkaline earth metal that is also softer than calcium. Strontiumcompoundsare quite common and also have a selection of uses—from fireworks to cement come toothpaste. In fireworks, strontium compounds produce deep red explosions. In toothpaste, prefer the one pictured in theFigurebelow, the compound strontium chloride reduces this sensitivity.



· facets in team 2 of the regular table are called alkaline earth metals. They space silvery or gray incolor. They space also fairly soft and low in density.

· Alkaline planet metals are very reactive because they readily provide up their two valence electrons to achieve a complete outerenergy level, which is the most stable arrangement of electrons. Reactivity increases from the top to the bottom the the group.

· examples of alkaline earth metals incorporate calcium, i m sorry is required for solid bones, and strontium, which is used for do cement and also other products.

Explore More

At the following URL, observe how four various alkaline planet metals reaction withwater. After you watch the video, answer the concerns below.


1. Watch the reaction in the video, and then rank the alkaline planet metals from many to the very least reactive through water.

2. What defines the distinctions in reactivity?

3. Guess the reactivity that beryllium v water. Wherein would that fit in your ranking?

4. Whatsubstancesare created in each reaction the you observed in the video?


1. What space alkaline planet metals? What space their physics properties?

2. Why are alkaline planet metals really reactive?

3. Compare and contrast the reactivity that beryllium (Be) and barium (Ba).

Noble Gases

Characteristics of team 18 of the routine table.

· recognize the noblegases.

· list properties of noblegases.

· describe the nonreactivity that noblegasesand exactly how it is regarded theoctet rule.


Okay, helium balloons room light, yet they’re not that light! This fanciful snapshot serves to do the point that helium is among the lightestelements. Helium belongs to a group of aspects called the noble gases.

What room Noble Gases?

Noble gasesare nonreactive, nonmetallicelementsin team 18 that the routine table. Together you deserve to see in the routine table inFigurebelow, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and also radon (Rn). All noble gases are colorless and also odorless. They also have lowboilingpoints, explaining why they space gases at roomtemperature. Radon, at the bottom that the group, is radioactive, so it constantly decays to otherelements. For terrific overview the the noble gases, watch the video clip at this URL:


· come learn just how the noble gases were discovered, go to this URL:http://www.youtube.com/watch?v=ceQMs30D16E.

· come explore details noble gases, click on their icons in the periodic table in ~ this URL:http://www.ptable.com/.


Q:Based on their position in the routine table (Figureabove), how countless valenceelectronsdo you think noble gases have?

A:The variety of valenceelectronsstarts in ~ one for elements in group 1. That then rises by one indigenous left come right across each duration (row) the the periodic table for teams 1–2 and also 13–18. Therefore, noble gases have eight valence electrons.

Chemical properties of Noble Gases

Noble gases are the least reactive of all known elements. That’s because with eight valenceelectrons, their outer power levels space full. The only exception is helium, which has just two electrons. But helium additionally has a full outerenergy level, because its only energy level (energy level 1) deserve to hold a best of 2 electrons. A full outer power level is the most stable setup of electrons. As a result, noble gases cannot become much more stable by reaction with other elements and gaining or losing valence electrons. Therefore, noble gases room rarely associated inchemical reactionsand almost never formcompoundswith various other elements.

Noble Gases and also theOctet Rule

Because the noble gases space the least reactive of all elements, your eight valence electron are used as the typical for nonreactivity and also to explain how other aspects interact. This is declared as the octet (“group of eight”) rule. According to this rule,atomsreact come formcompoundsthat permit them to have a group of eight valence electrons favor the noble gases. For example, sodium (with one valence electron) reacts v chlorine (with seven valence electrons) to kind the secure compound sodium chloride (table salt). In this reaction, sodium donates an electron and also chlorine accepts it, giving each facet an octet of valence electrons.

Some provides of Noble Gases

Did you ever get helium balloons like those in the opening picture? unlike a balloon filled through air, a balloon filled with helium requirements to be weighted down so the won’t float away — although you don’t have to use one elephant!.

Q:Why walk a helium balloon float far if it’s not weighted down?

A:Heliumatomshave just twoprotons, twoneutrons, and two electrons, so they have less massive than any type of other atoms other than hydrogen. Together a result, helium is lighter 보다 air, explaining why a helium balloon floats up right into the air uneven weighted down.

Early incandescent irradiate bulbs, like the one pictured in theFigurebelow, didn’t last really long. The filaments quickly melted out. Although air to be pumped the end of the bulb, it wasn’t a finish vacuum. Oxygen in the tiny amount of air continuing to be inside the light bulb reacted through the metal filament. This corroded the filament and also caused dark store on the glass. Pour it until it is full a light bulb with argon gas avoids these problems. That’s why modern-day light bulbs are filled v argon.

Q:How go argon stop the troubles of early on light bulbs?

A:As a noble gas through eight electrons, argon doesn’t react v the steel in the filament. This protects the filament and keeps the glass blub totally free of deposits.


Noble gases are additionally used to fill the glass pipe of lighted indications like the one in theFigurebelow. Although noble gases are chemically nonreactive, your electrons have the right to be energized by sending out anelectric currentthrough them. As soon as this happens, the electrons run to a higherenergy level. When the electrons go back to their original power level, they offer off energy as light. Different noble gases provide off irradiate of different colors. Neon provides off reddish-orange light, choose the native “Open” in the authorize below. Krypton provides off violet light and xenon gives off blue light.



· Noble gases space nonreactive, nonmetallic facets in team 18 that the routine table.

· Noble gases room the least reactive of all elements. That’s because they have actually eight valence electrons, which fill their outerenergy level. This is the most stable arrangement of electrons, so noble gases seldom react with various other elements and formcompounds.

· Theoctet rulestates thatatomsreact to kind compounds that allow them to have actually eight valence electrons choose the noble gases, which room the the very least reactive elements.

· Noble gases are supplied for balloons, light bulbs, and also lighted signs.

Explore More

Watch the video about noble gases in ~ the complying with URL, and then price the inquiries below.


1. Compare and also contrast the reactivity of the aspects helium, neon, argon, krypton, and xenon.

2. Compare the density of these noble gases to the thickness of air.

3. Describe how the mass of noble gases transforms from the peak to the bottom of team 18.


1. What room noble gases?

2. Explain why noble gases are almost totally nonreactive.

See more: How To Make Tobacco In Little Alchemy ? How To Make 'Tobacco' In Little Alchemy 2

3. What is the octet rule? exactly how is it concerned noble gases?

4. Hydrogen (H) atoms have one electron and exist as diatomic (“two-atom”) molecule (H2). Helium atoms have two electrons and also exist just as single helium atoms. Define why hydrogen and also helium differ in this way.