Chemistry Chapter 5

11/9/15 What group from the Alkali metals? What are 2 properties of the Alkali metals?

1. Alkali metals do not occur in nature as free elements 2. Alkali metals consist of atoms with one electron in the outermost energy level

11/9/15 What are 2 properties of Alkaline Earth Metals?

1. Alkaline earth metals do not occur in nature as free elements.....they occur as compounds (attached to other molecules). 2. They are insoluble in water (unlike alkali compounds....which are very soluble in water....like NaCl). 3. They are less reactive than alkali metals.

Blue worksheet What is the pattern of atomic radii: 1. left to right? 2. top to bottom? Which atom is smallest? Which atom is largest?

1. Left to right = decrease (atoms get smaller from left to right on the periodic table) 2. top to bottom = increase (atoms get bigger from top to bottom....as energy shells are added). This is a general trend with several exceptions. Look at group 13 Al and Ga. Helium - smallest (31 picometers) Francium - biggest (270 picometers)

11/9/15 What are 2 applications of halogens?

1. chlorine in water treatment 2. fluoride and tooth decay

11/9/15 What are 2 uses of alkaline earth metals?

1. fireworks 2. diet - calcium and magnesium are essential minerals in the diet

11/9/15 What are 2 applications of Alkali metals?

1. sodium vapor lighting 2. electrolyte balance in the body

When were the noble gases added to the periodic table?

1898 (Ramsay). In 1894 William Ramsay and Lord Rayleigh discovered Argon. They realized that it was nonreactive.....like helium. In order to fit argon and helium into the periodic table, Ramsay proposed a new group. He later discovered krypton and xenon.

How many periods in the periodic table?

7

What is a cation? What is an anion? How do their sizes compare to neutral atoms?

A cation is a positive ion....caused by the loss of an electron. A loss of an electron causes a decrease in atomic radius. When you remove an electron, the nuclear magnet pulls harder on the remaining electrons and the electron cloud shrinks. An anion is a negative ion.....caused by the gain of an electron. A gain of an electron causes an increase in atomic radius. When you add an electron, the nuclear magnet pulls more weakly because it is spread out over more electrons. Also, the cloud spreads out because of greater repulsion between electrons.

11/9/15 How can we detect Alkali metals?

Alkali metals are easily detected by flame tests because each metal imparts a characteristic color to a flame.

When d-block elements react, which electrons are removed first?

Although newly added electrons occupy the d sublevels, the first electrons to be removed are those in the outermost s sublevels. For example, Iron (Fe) has the electron configuration [Ar] 3d6 4s2 First it loses two 4s electrons then can lose a 3d electron. Most d-block elements commonly form 2+ ions in compounds. Some, such as iron and chromium, also commonly form 3+ ions. Group 3 only forms ions with 3+ charge Copper forms +1 and +2 ions Silver usually only forms +1 ions

What is an ion?

An ion is an atom or group of bonded atoms that has a positive or negative charge. For example, Na+ has lost an electron. It has a positive charge and is a cation Cl- has gained an electron. It has a negative and is called an anion. MnO4- is a permanganate ion. It is a group of bonded atoms that has a negative charge

What is ionization?

Any process that results in the formation of an ion is referred to as ionization.

Why does ionization energy decrease from top to bottom?

As you go down the periodic table from top to bottom, you add energy shells. The electrons in the outer shells are farther from the nucleus and are less tightly bound. These "far away" electrons are easier to pull off. This is why ionization energy decreases from top to bottom. Another reason is the "shielding effect." As electron layers are added, they push away outer electrons.....they form a shield between the nucleus and the outer electrons....making outer electrons even less tightly bound. A big atom like Francium has many, many interior electrons shielding it from the nucleus.

Blue worksheet What is Atomic Radius?

Atomic radius is one half the distance between the nuclei of identical atoms that are bonded together (we do it this way because it's hard to measure the radius of a single atom with fuzzy edges).

d-block 11/9/2015 What is the format for group 3 elements? Using a periodic table, tell the electron configuration for yttrium? (group 3 are the d-block group starting with Scandium)

Atoms of the d-block contain from zero to two electrons in the s orbital of their highest occupied energy level and one to ten electrons in the d sublevel of the next-lower energy level. The format for group 3 is: (n-1) d1 ns2 For example, yttrium is a d-block element in group 3. It is in period 5. The last part of its electron configuration is: 4d1 5s2 the complete formula for yttrium is: [Kr] 4d1 5s2

Name the 7 metalloids.

B, Si, Ge, As, Sb, Te, Po

Name the 6 alkaline earth metals.

Be, Mg, Ca, Sr, Ba, Ra (not to be confused with Rn)

11/9/15 Hydrogen is 1s1 Why isn't hydrogen included in group one? Why is it all by itself in the top left corner?

Despite having the same "s1" electron configuration as group 1, hydrogen does not share the same properties as the elements of group 1......it is an invisible, odorless gas.....not a metal like group 1 elements.

Which have greater electron affinity, metals or nonmetals?

Electron affinity increases from left to right. Nonmetals have greater electron affinity. They pull harder on electrons.

What is electron affinity?

Electron affinity is the energy change that occurs when an electron is acquired by a neutral atom. Most atoms give off energy when they acquire an electron. The energy given off is in kilojoules per mole. How strongly a magnet snaps depends on the strength of the magnet.

What is electronegativity?

Electronegativity is a measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound. The most electronegative element is fluorine. It is arbitrarily assigned a value of 4. Alkali and alkaline-earth metals are the least electronegative. Most noble gases don't form compounds and therefore cannot be assigned electronegativities.

11/9/15 Halogen Family What are the 5 halogens?

F, Cl, Br, I, At (Astatine) F, Cl, Br are gases. Iodine is a purple solid that sublimates (like dry ice). Astatine is a radioactive solid. Elemental astatine has never been viewed because any macroscopic sample would be immediately vaporized by its radioactive heating. A total of 0.05 micrograms (0.00000005 grams) of astatine have been produced to date. Astatine has a half-life of 8 hours. Nobody has ever seen Astatine.

11/9/15 How can alkaline earth metals be identified?

Flame tests can be used to identify three of the alkaline earth elements

11/9/15 What governs an atom's chemical properties?

Generally, the electron configuration of an atom's highest occupied energy level (valence electrons) governs the atom's chemical properties. (this actually doesn't work all that well for transition elements or for the f-block elements)....it mostly just works for groups s and p block elements.

Which GROUP has the lowest ionization energy? Which group has the highest?

Group 1 has the lowest. Group 18 has the highest.

p-block 11/9/2015 What are the most reactive nonmetals? Why are they so reactive?

Halogens (group 17) are the most reactive nonmetals. Their reactiviness is based on the presence of 7 electrons in their outer energy level (they desperately need one more electron to have a stable octet).

11/9/15 Halogen Family Are halogens metals? What do they usually combine with?

Halogens are nonmetal gases. In nature they often combine with with metals to form metal hallides (NaCl is a metal hallide).

11/9/15 Why is helium included in group 18?

Helium is 1S2. It is included in group 18 because it possesses a special chemical stability, exhibiting the unreactive nature of a group 18 element (it is unreactive....just like the other nobel gases)

How many elements are in period 4? Why?

In period 4 there are 18 elements. The sublevels of period 4 fill up like this : 1. the 4s orbitals fill up with 2 electrons 2. the 3d orbitals fill up with 10 electrons 3. the 4p orbitals fill up with 6 electrons 2+10+6 = 18 There are 18 elements in period 4 because it takes 18 electrons to fill the 4s, 3d and 4p sublevels.

11/9/15 Why are there 8 elements in period 2?

In the second period, the 2s and 2p subleveels can hold 2 and 6 electrons respectively. Consequently, the second period totals eight elements.

Which sublevels are being filled in the second period? How many elements are in the second period and why?

In the second period, the 2s sublevel and 2p sublevel are being filled. It takes 2 electrons to fill the s sublevel and 6 electrons to fill the p sublevel. 2+6 = 8.

Why does ionization energy increase from left to right?

Increased nuclear charge from left to right more strongly attracts electrons in the same energy level (the magnet gets bigger and stronger.....and pulls electrons in tighter......making it harder to rip off an electron). From left to right, the magnet pulls harder......atomic radius decreases.....ionization energy increases. Increasing nuclear charge is responsible for both increasing ionization energy and decreasing radii across the periods.

What is the difference between ionization energy electronegativity electron affinity? What are the trends for all 3?

Ionization energy - the energy required to pull away one electron Electronegativity - how hard an atom pulls on electrons. How good an atom is at stealing electrons Electron affinity - how much energy is released (snap) when a neutral atom captures an extra electron. All 3 increase from left to right and decrease from top to bottom (with several exceptions).

Why does ionization energy increase for successive electrons removed......why does it get harder and harder to pull each additional electron?

Ionization energy keeps increasing as you keep pulling off more electrons. You have to pull harder and harder for each additional electron that you remove. As electrons are removed, fewer electrons remain within the atom to shield the attractive force of the nucleus.....the remaining electrons get pulled in closer and tighter. As you keep pulling off electrons, the atom will eventually have an outer shell with 8 electrons. When this happens, the atom's outer shell resembles that of a noble gas. Once the electron reaches this point, there is a big jump in ionization energy because it becomes really hard to pull off another electron. For example, Lithium is [He]2s1. If you take away one electron, you are left with [He]....which has the same electron configuration as helium.....and it is much, much harder to pull an electron from this very stable configuration. Carbon is [He]2s2 2p2. If you pull off 4 electrons, you are left with [He]. To pull off a 5th electron takes much more energy. Look at the picture and see the big jumps in the yellow highlights. These jumps occur when an ion assumes a noble-gas configuration.

What does Kj/mol mean? How does it apply to electron affinity?

It means kilojoule per mol. A typical donut has 300 calories of energy stored in it. A dozen donuts has 3,600 calories of energy. So, a dozen donuts have 3600 cal/dozen.....or 3.6Kcal/doz In the same way.....energy in chemical reactions is measured in kilojoules per mol.....a mole is 6.022 x 10^23 of anything If you look at the periodic table of electron affinities, you will see a number under each element. This number is the amount of energy (in Kilojoules) that is given off when 1 mol of atoms accept one electron each. When an atom steals (accepts) an electron, it gives off energy.....SNAP!!! On the table, atoms with zero electron affinity can't readily be measured because they don't easily accept electrons.

Name the 6 Alkali metals.

Li, Na, K, Rb, Cs, Fr

Who was Henry Moseley and what did he do?

Mendeleev noticed that most elements could be arranged in order of increasing atomic mass, but a few could not. In 1911, Henry Moseley, working with Ernest Rutherford examined the spectra of 30 metals. He saw that the elements fit better into the periodic table when arranged by the number of protons.

On the periodic table, where are you likely to find cations? Anions?

Metals at the left tend to form cations. Nonmetals at the upper right tend to form anions.

d-block 11/9/15 Do all d-block elements have identical outer electron configurations?

No. d-block elements do not necessarily have identicla outer electron configurations down a group. For example, if you take any group in the s-block or p-block, they will all have the same pattern of electron configurations. This is not true for every group in the d-block. For example, in group 9 you have: Co - 3d7 4s2 Rh - 4d8 5s1 Ir - 5d7 6s2

How many elements are in period 5?

Period 5 is the same as period 4.....there are 18 elements.

How many elements are in period 6? What sublevels are being filled? (use a periodic table with electron configurations and follow along with the explanation on the back of this flashcard).

Period 6 has 32 elements. Period 6 fills up like this: 1. the 5 s orbitals fill up with 2 electrons (cesium and barium) 2. the 5d orbital gets one electron (Lanthanum) 3. then, something weird happnes.....the 5d orbital doesn't get any more electrons.....and the 4f orbitals start filling up......one by one.....until the 4f sublevel is full with 14 electrons. 4. After the 4f level is full, the 5d orbitals continue filling up....starting with Hafnium. 5. The 4f orbitals are all fulled up with 14 electrons by the time you get to Mercury (Hg). 6. Then, after mercury, the 6p orbitals start filling up until they have 6 electrons Radon is the last element in period 6. It is: [Xe] 4f14 5d10 6s2 6p6 14+10+2+6 = 32 Period 7 fills up in a similar way to period 6

How many elements are in period 3 and which sublevels are being filled?

Period three has 8 elements. Sublevel 3s and 3p are being filled.

If you want to remove an electron from an atom, what do you need?

Removing electrons from atoms requires energy.

Which sublevel is being filled in the first period? How many elements are in the first sublevel and why?

The 1s sublevel is being filled. It can hold only 2 electrons, which is why there are only 2 elements in the first period.

What are the actinides? Which orbitals are filling up? Why are the lanthanides and actinides set off below the main portion of the periodic table?

The actinides are the 14 elements of with the numbers 90 to 103. (thorium to lawrencium). The "5f" orbitals are filling up. To save space, the lanthanides and actinides are usually set off below the main portion of the periodic table.

Why does the DIFFERENCE in radii between neighboring atoms in each period grow smaller.

The attraction of the nucleus is somewhat offset by repulsion among the increased number of electrons in the same outer energy level. As a result, the difference in radii between neighboring atoms in each period grows smaller. (as the electrons are pulled together by the increasing charge of the nucleus, they repell harder as they are condensed)

d-block 11/9/15 What is another name for "d-block" elements? What are their properties?

The d-block elements are metals with typical metallic properties and are often referred to as "transition elements." They are good conductors of electricity and have high luster (bright and shiny).

What are valence electrons?

The electrons available to be lost, gained, or shared in the formation of chemical compounds are referred to as valence electrons. For main-group elements (s block and p block), the valence electrons are the electrons in the outermost s and p sublevels. Inner electrons are held too tightly by the nucleus to be involved in chemical reactions. Group 1 elements have 1 valence electron Group 2 elements have 2 valence electrons. Groups 13-18 have a number of valence electrons equal to the group number minus 10. d-block elements have electrons in the d sublevel and s sublevel available for interactions with their surroundings.

What is second ionization energy IE2, third ionization energy IE3, and so on? Is second ionization energy greater or less than first ionization energy?

The energies for removal of additional electrons from an atom are referred to as the second ionization energy. Same for third, fourth, fifth.... Each additional electron that you rip off an atom takes more and more energy. Let's take Boron as an example: 1st ionization energy: 801 KJ/mol (kilo joules per mole) 2nd ionization energy: 2427 KJ/mol 3rd ionization energy: 3660 KJ/mol 4th ionization energy: 25,026 KJ/mol

What is ionization energy?

The energy required to remove one electron from a neutral atom of an element is the ionization energy, IE (or first ionization energy IE1). Note how the ionization energy increases from left to right until it gets to a noble gas......then drops dramatically (because a new shell is added) Note also that there is a smaller drop when going from the d-block to the p-block: Zinc (d block) to Gallium (pblock) Cadmium (d block) to Indium (p block) Mercury (d block) to Thallium (d block)

f-block 11/9/2015 In what periods are the f-block elements? How many f-block elements in each row? In what group are the f-block elements?

The f-block elements are in the 6th and 7th periods. There are 14 f-block elements in each row (because it takes 14 electrons to fill an f orbital). The f-block elements are not part of any group on the periodic table. They are quite lonely.

What are the lanthanides? Which orbitas are filling up? When were they discovered? Why was it difficult to identify them?

The lanthanides are the 14 elements with atomic numbers 58 (cerium) to 71 (lutetium). The "4f" orbitals are filling up. Because these elements are so similar in properties, the process of separating and identifying them was a tedious task involving many chemists.

11/9/15 What determines the length of a period?

The length of each period is determined by the number of electrons that can occupy the sublevels being filled in that period.

p-block 11/9/2015 What are "main group elements?"

The p-block elements together with the s-block elements are called the main group elements.

What is the periodic table?

The periodic table is an arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column, or group.

What is the periodic law?

The physical and chemical properties of the elements are periodic functions of their atomic numbers (number of protons).

11/9/15 How can the presence of each of the halogens be determined?

The presence of each of the halogens can be determined by atomic absorption spectoscopy.

Why do atoms get smaller from left to right?

The trend to smaller atoms across a period is caused by the increasing positive charge of the nucleus (magnet gets stronger). As electrons add to s and p sublevels in the same main energy level, they are gradually pulled closer to the more highly charged nucleus. This increased pull results in a decrease in atomic radii

Are groups horizontal or vertical?

Vertical

11/9/15 How can the period of an element be determined from the element's electron configuration?

You can tell the period of an element by looking at its highest occupied energy level. For example, Arsnec is: [Ar] 3d10 4s2 4p3 The "4" indicates the highest occupied energy level.....therefore, arsenic is in the fourth period.

d-block 11/9/15 What is higher in energy.....a 3d sublevel or a 4s sublevel.

You would think that 4s is higher than 3d since 4 is bigger than 3.....but it snot. The 3d sublevel is slightly higher in energy than the 4s sublevel, so the 4s sublevel (which is lower) gets filled before the 3d sublevel. Like this: 4s2 3d7

d-block 11/9/15 What are some properties of d-block elements?

d-block elements are metals with typical metallic properties and are often referred to as transition elements. They are good conductors of electricity and have high luster.

d-block 11/9/15 Do d-block elements have identical outer electron configurations? (like the s-block and p-block)

d-block groups do not necessarily have identical outer electron configurations.

11/9/15 What are some properties of group 1 elements?

group 1 elements: 0. aka "Alkali Metals" 1. They are all "s-block" 2. they are soft, silver metals and are more reactive than group 2 3. group 1 elements are extremely reactive 4. they melt at a lower temperature than other metals

p-block 11/9/15 What is the format of the electron configuration for group 13 and group 14?

group 13: ns2 np1 group 14: ns2 np2

11/9/15 What are some properties of group 2 elements?

group 2 elements: 0. AKA "Alkaline Earth Metals" 1. harder, denser, stronger than alkali metals 2. metals have no special stability (they are less reactive than group 1.....but still pretty reactive) 3. they have higher melting points than group 1

Are periods horizontal or vertical?

horizontal

p-block 11/9/2015 What types of elements are in the p-block? Wood? Air? Koolaid?

p-block elements are either metals, nonmetals or metalloids.

p-block 11/9/15 How do you figure out the number of electrons in the highest occupied energy level for p-block elements (the valence electrons)?

total # of electrons in the highest occupied energy level is equal to the group number minus 10. For example, group 13 elements have three (13-10 = 3) electrons in the highest occupied energy level. To find the valence of p-block elements just used the second number of the group number (18 --> 8, 17-->7, 16-->6, 15-->5, etc...)

Who created the periodic table?

when the elements are arranged in order of increasing atomic mass, certain similarities in their chemical properties appear at regular intervals. Dmitri Mendeleev published his periodic table in 1869.