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Name: Empower YourselfChemistry Empower Your CommunityDate: Empower Your WorldPeriod:Today’s AIMs

SWBAT describe the historical development of the Periodic Table. SWBAT describe the general arrangement of the elements in the Periodic Table according to periodic

law (in groups and periods, in increasing atomic number).

Do Now1. Take out your Periodic Table. Examine the table and write 4 – 6 sentences hypothesizing about why the elements are arranged in the way that they are on the table. Be sure to add justifications for any patterns that you may observe.__________________________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Periodic Puzzle InvestigationDemetri Mendeleev’s discovery of the Periodic Law ranks as one of the greatest achievements in the history of science. It has survived the test of time and stands to this day as the single most important tool to understand the chemistry of the elements. As we try to understand the essence of this great discovery, it is worthwhile to go back in time and look at how it was achieved. What did Mendeleev know and when did he know it?

The purpose of this activity is to re-create Mendeleev’s discovery of the classification of the elements and the Periodic Law using a special deck of element cards. As the cards are arranged and rearranged based on logical trends in some of these properties, the nature of the Periodic Law should reveal itself.

Procedure1. Obtain a deck of Periodic Trend cards and board with pre – labeled cards.2. Working in a collaborative manner, discuss the possibilities for arrangement of the unknown element cards with all members of the group, and look for a logical arrangement of the cards. Consider the following questions:

What are the similarities and differences among the elements? Are there any or logical trends in their properties?

NOTE: There are specific spots for the unknown cards, place them based on similar properties, do not place them randomly. 3. Once you have correctly placed the unknown cards, identify the name of each element using the modern Periodic Table that is in your Regents Reference Tables. Identify each of the unknown elements and their names in the table below:

Unknown Symbol Element Name1

2

COURSEWORK/PACKETS Pg. # _________

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3

4

5

6

7

8

9

Periodic Puzzle Questions:1. Mendeleev’s Periodic Law can be states: “The physical and chemical properties of elements are periodic functions of their atomic masses”. Looking at your arrangement of the element cards, describe in your own words what the term “periodic function” means.__________________________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. Some of the properties on listed on each card are periodic properties, others are not. Name one property that is periodic and one that is not.__________________________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Mendeleev’s table is arranged in order of increasing atomic mass. The elements on the modern Periodic Table are arranged in order of increasing atomic number. During Mendeleev’s time, Dalton’s model of the atom was the accepted model of the atom. Why didn’t Mendeleev use the atomic number to arrange the elements?__________________________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

4. Mendeleev’s greatest insight in creating the Periodic Table was in recognizing there were some gaps when the elements were arranged in logical order. He had the courage not only to leave blanks in his table for the


Name: Empower YourselfChemistry Empower Your CommunityDate: Empower Your WorldPeriod:missing elements, but also to predict their properties. How do you think scientists were able to fill in the gaps for the elements that were “missing” from Mendeleev’s original table?__________________________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Periodic Video QuestionsWhy was Mendeleev’s Periodic Table seen as so revolutionary? Be Specific



Exit Ticket 2.1 – Periodic Puzzles1. Elements on the Periodic Table are organized in order of increasing:

a. Atomic Massb. Atomic Numberc. Electronegativityd. Ionization Energy

2. Mendeleev’s Periodic Table organized elements in order of increasing:a. Atomic Massb. Atomic Numberc. Electronegativityd. Ionization Energy

3. Why did Mendeleev have gaps in the original Periodic Table that he created?____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

4. On the table below label groups and periods:



HOMEWORK 2.1 – Periodic Puzzles

Read the extract from a “Short History of Nearly Everything” by Bill Bryson. Then answer the questions that follow.

Mendeleyev (also sometimes spelled Mendeleev or Mendeleef) was born in 1834 at Tobolsk, in the far west of Siberia, into a well-educated, reasonably prosperous, and very large family – so large, in fact, that history has lost track of exactly how many Mendeleyevs there were: some sources say there were fourteen children, some say seventeen. All agree, at any rate that Dmitri was the youngest. Luck was not always with the Mendeleyevs. When Dmitri was small his father, the headmaster of a local school, went blind and his mother had to go out to work. Clearly an extraordinary woman, she eventually became the manager of a successful glass factory. All went well until 1848, when the factory burned down and the family was reduced to penury. Determined to get her youngest child an education, the indomitable Mrs. Mendeleyev hitchhiked with young Dmitri four thousand miles to St. Petersburg – that’s equivalent to traveling from London to Equitorial Guinea – and deposited him at the Institute of Pedagogy. Worn out by her efforts, she died soon after.Mendeleyev dutifully completed his studies and eventually landed a position at the local university. There he was a competent but not terribly outstanding chemist, known more for his wild hair and beard, which he had trimmed just once a year, than for his gifts in the laboratory.

However, in 1869, at the age of thirty-five, he began to toy with a way to arrange the elements. At the time, elements were normally grouped in two ways- either by atomic weight (atomic mass) or by common properties (whether they were metals or gases, for instance). Mendeleeyev’s breakthrough was to see that the two could be combined in a single table.

As is often the way in science, the principle had actually been anticipated three years previously by an amateur chemist in England named John Newlands. He suggested that when elements were arranged by weight they appeared to repeat certain properties – in a sense to harmonize – at every eighth place along the scale. Slightly unwisely, Newlands called it the Law of Octaves and likened the arrangement to the octaves on a piano keyboard. Perhaps there was something in Newland’s manner of presentation, but the idea was considered fundamentally preposterous and widely mocked. At gatherings, droller members of the audience would sometimes ask him if he could get his elements to play them a little tune. Discouraged, Newlands gave up pushing the idea and soon dropped from view altogether.

Mendeleyev used a slightly different approach, placing his elements into groups of seven, but employed fundamentally the same principle. Suddenly the idea seemed brilliant and wondrously perceptive. Because the properties of the elements repeated themselves periodically, the invention became known as the periodic table.

Mendeleyev was said to have been inspired by the card game known as solitaire in North America and patience elsewhere, wherein cards are arranged by suit horizontally and by number vertically. Using a broadly VOCABULARYpenury extreme poverty indomitable brave, determined pedagogy teaching amateur unskilled mocked make fun of droller amusingly odd preposterous absurd properties characteristics

COURSEWORK/PACKETS Pg. # _________HOMEWORK


similar concept, he arranged the elements in horizontal rows called periods and vertical columns called groups. This instantly showed one set of relationships when read up and down and another when read from side to side. Specifically, the vertical columns (the groups) put together chemicals that have similar properties. Thus copper sits on top of silver and silver sits on top of gold because of their chemical affinities as metals, while helium, neon and argon are in a column made up of gases. The horizontal rows, meanwhile, arrange the chemicals in ascending order by the number of protons in their nuclei – what is known as the atomic number. Hydrogen has just one proton, and so it has an atomic number of one and comes first on the chart; uranium has ninety two protons, and so it comes near the end and has an atomic number of ninety-two. In this sense, as Philip Ball has pointed out, chemistry really is just a matter of counting.

There was still a great deal that wasn’t known or understood. Hydrogen is the most common element in the universe, yet no one would guess as much for another thirty years. Helium, the second most abundant element, had only been found the year before – its existence hadn’t even been suspected before that – and then not on Earth but in the Sun, where it was found with a spectroscope during a solar eclipse, which is why it honors the Greek sun god of Helios. It wouldn’t be isolated until 1895. Even so, thanks to Mendeleyev’s invention, chemistry was now on a firm footing.

Today we have “120 or so” known elements – ninety two naturally occurring ones plus a couple of dozen that have been created in labs. The actual number is slightly contentious because the heavy, synthesized elements exist for only millionths of seconds and chemists sometimes argue over whether they have really been detected or not. In Mendeleyev’s day just sixty-three elements were known, but part of his cleverness was to realize that the elements as then known didn’t make a complete picture, that many pieces were missing. His table predicted, with pleasing accuracy, where new elements would slot in when they were found.

No one knows, incidentally, how high the number of elements might go, though anything beyond 168 as an atomic weight is considered “purely speculative”, but what is certain is that anything that is found will fit neatly into Mendeleyev’s great scheme.

VOCABULARYcontentious quarrelsome speculative forming an opinion not based on fact

Using the extract, answer the questions below in full sentences.

1) Why did Mendeleyev name the Periodic Table, the “Periodic Table”?__________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________

2) How are the elements arranged in the Periodic Table?__________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________



3) What is interesting about all the elements in a group?__________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________

4) Why are copper, silver and gold in the same group?__________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________

5) Why are helium, argon and neon in the same group?__________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________

6) How are the elements in each period arranged?__________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________

7) Why did Mendeleev leave gaps in the Periodic Table?__________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________

8. As a member of a newly inhabited space station Alpha, you are given the task of organizing information on newly discovered elements as it comes in from the laboratory. To date, five elements have been discovered and have been assigned names and symbols from the Greek alphabet. An analysis of the new elements has yielded the following data.

Element Name Atomic Number Atomic Mass Properties

Epsilon ε 23 47.33

Nonmetal, Gas, Very reactiveProduces a salt whencombined with a metal

Betaβ

13 27.01

Metal, Soft solid, Very ReactiveLow melting point

Gamma γ 12 25.35

Nonmetal, Gas, Extremely unreactive



DeltaΔ 4 7.98

Nonmetal, Very abundantReacts with most other elements

LambdaΛ

9 16.17Metal, Solid, Good conductorHigh luster, Hard Dense

a. Applying Models: Use the template on the next page to create a Periodic Table based on the properties of the five new elements. Organize the table just like the modern Periodic Table . So ask yourself: Is the modern periodic table arranged in order left to right in increasing atomic mass or atomic number? Make sure, like Mendeleev, you leave gaps for elements still yet to be discovered.

b. Predicting Outcomes: Using your newly created Periodic Table, predict the atomic number of an element with an atomic mass of 11.29 that has nonmetal properties and is very reactive. Explain your choice: ________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________

c. Predicting Outcomes: Predict the atomic number of an element having an atomic mass of 15.02 that exhibits metallic properties but is softer than lambda and harder than beta.Explain your choice: ________________________________________________________________________________________________ ________________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________


Name: Empower YourselfChemistry Empower Your CommunityDate: Empower Your World Period:

Periodic Table It may help to answer questions b and c if you add into the periodic table not only the atomic number and mass of each element but also the elements properties.


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Weeblydpchemistry.weebly.com/.../8/4/9/8849208/2.1.periodic_ta… · Web viewHydrogen is the most common element in the universe, yet no one would guess as much for another thirty