Periodic Table Lab Report PDF

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General Chemistry I Laboratory Session 7 - Periodic Table of Elements

Alejandra Gutiérrez Cortés Daniel Castañeda Ruan Magda Figueroa Diaz M.Sc. Paola Camacho Durán

Session Date - 03/05/2021 Submission Date - 03/11/2021

Introduction In this practice, the team is expected to learn about the periodic table, its components, organization and why it is such a helpful tool used by many scientists in the fields of chemistry, nuclear physics and biologists. In a periodic table, the elements are arranged the way they are due to the characteristics that they possess, such as atomic number, electron, configuration, among other properties. The elements are arranged into groups,

the horizontal rows are called periods while the vertical columns are called groups.

Russian chemist Dimitri Mendeleev was the first one who created a table that helped establish the characteristics of different elements. The modern version of the periodic table was developed using the same idea. When all of the known chemical elements were arranged in increasing atomic weight order, Mendeleev discovered that the resulting table revealed a recurring pattern, or periodicity, of properties within groups of elements. Thus, it is relatively easy to predict the chemical properties of an element if one knows the properties of the elements around it. The modern periodic table can be divided in many ways, but one of the most commonly known is the division of metals, nonmetals and metalloids. Metals are elements that are usually solid, shiny, ductile and good conductors of both electricity and heat. Nonmetals are elements which lack those metallic properties, they tend to have low melting and boiling points, as well as low density. These can exist as liquids, solids or gases.

Finally, metalloids are akin to metals, yet they can possess properties of both metals or nonmetals. One can distinguish between different metals with the Flame Test, which depends on the emission spectrum produced when a solution is set by a flame. By doing this procedure, the heat excites the valence electrons who will produce a specific wavelength of visible light as they fall back to their original state. Valence electrons are located in the outermost shell of an atom. Most metal ions have a known flame color when applied to a flame test.

Other types of information that can be provided by the periodic table are oxidation states. The oxidation state is defined as the normal charge an atom would have assuming all bonds are ionic. This is extremely useful for balancing equations. Finally, one can identify certain different trends like electronegativity, ionization energy and atomic radius. The first two follow the same pattern, while the atomic radius decreases moving down.

Objectives At the end of this simulation, you will be able to… ● Describe the structure and organization of the periodic table ● Classify elements of a family based on their location in the periodic table ● Distinguish metals from other element classes based on typical characteristics ● Use the flame color test to identify metals based on their position in the periodic table ● Relate valence electrons and oxidation state of a main group element to its position in the periodic table ● Describe the main trends among groups and periods for atomic properties ● Explain the causes on the atomic level for the main trends among groups and periods concerning atomic radii, ionization energy and electronegativity

Materials and Methods For this practice, Labster’s simulation for the periodic table will be used: https://api2.labster.com/ref/8dd4970f644e447/simulation/a0K2X00000jGm8mUAC The techniques used in the lab will be the flame color test. The flame color test required the observation of shininess of Sodium (Na), Phosphorus (P), Copper, (Cu), and Calcium (Ca) by grabbing them with forceps and seeing if they reflected light. The electric conductivity and ductility were given by the simulation. To actually try the flame test, a wire loop was used. This loop was cleaned by dipping it in hydrochloric acid and then in water, then holding it to the fire to remove any residual ions. Now, the wire loop was dipped in Calcium Chloride ( CaCl 2 ),Sodium Chloride( Na Cl❑ ), and Copper Chloride ( CuCl 2 ). The wire loop was cleaned in between uses. After being dipped, the wire loop was held to an active Bunsen burner to see the color of the flame that it produced. Personal safety equipment Safety goggles and proper clothing required. Wash hands when leaving the laboratory. Eye exposure: Immediately flush with fresh water for at least 15 minutes. No food or drink in the laboratory. Gloves to help prevent contact.

Results I) 1. Which are the main characteristics that differentiate metals from nonmetals and metalloids? - Metals are shiny, good conductors and ductile while nonmetals are quite the opposite. 2. Which is the main use for metalloids in the modern industry of informatics and telecommunications? 3. What application can you use for the ductility of metals like copper and gold? 4. Does the position of an element in the periodic table describe the properties of an element? - Yes, the position of each element in the table gives important information about its structure, properties, and behavior in chemical reactions. 5. How do you represent the mass number and the atomic number? - By using the symbol Z.

6. Research about what an isotope is and what the average mass is.

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An isotope is one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behaviour but with different atomic masses and physical properties, the average mass is the sum of the isotope.

II) 1. What information does the groups column in the table give you? - Elements in their same group have the same electron configuration in their valence shell 2. What information does the period line in the table give you? - Elements in the same period have the same number of electron shells. 3. Explain what the natural characteristics of Hydrargyrum are. What is the modern name for that element? Research about the Hazard symbol that corresponds for this metal. Where can you find this symbology present in the simulation? - Unlike most other metals, Mercury (Hg) has the unique characteristic of being a liquid at room temperature while still functioning like a metal. The hazard symbols used are the ones correspondent for toxic, health hazard, corrosive and environmental hazard. The simulation has a unique tab dedicated towards the hazards caused by mercury. III)

Element tests of properties 1. Which are the tests that the simulation suggests for identifying each element? What does shininess have to do with this evaluation? - The tests are ductility, electrical conductivity, flame test, looking for shininess, - Shininess is one of the different characteristics we already know about the elements. By using them, we can relate the ones given by each element and the ones that correspond to them. 2. Assign a color name and special property to the next elements: Ca, Cu, Ne, and Fe. - For Calcium: Orange; for Copper: green; for Neon: no color; for Iron: Iron. 3. What do cations and anions represent? In terms of properties, which elements prefer to remain as cations and which elements prefer to remain as anions? What does the family (or Group) tell you about the charge for each element? - The anions and cations represent a lack or excess of electrons. The anions and cations are related mostly to how close they are to completing the 8 electrons posed by the octet rule. And groups follow a charge they always have. This is related to their oxidation state, how like they are to lose electrons. 4. Which are all the main characteristics that differentiate the nonmetal element Phosphorous from the rest of the elements? Which is the most important one?

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Ductility, electrical conductivity, and shininess. Shininess is the most obvious one because it can be deduced from looking at the elements. 5. What does the colors of the flame test mean and demonstrate? - The color given by the flames are the ions released from the element. Essentially, when a particle is excited and brought to heat, one of the outer electrons jumps back to a closer orbital. This effect releases light and it “taints” the flame. IV) 1. What can you explain about the relationship between the Valence electrons and the family groups in the periodic table? - The valence electrons determine the family any given element is put on, elements on each family share the same number of valence electrons, thus, also sharing similar chemical characteristics. 2. What is a valence electron? - It is an electron of an atom that is located in the outermost orbit or valence orbit of said atom, this electron can be transferred to or shared with another atom. 3. The rule of the octet is useful to understand the number of electrons an atom wants to reach for stability, which are the atoms that clearly obey that rule? - The ones in family 8A, the noble gases. 4. What is the relationship between family and oxidation state? Show the figure provided in the simulation for your conclusions. - For A groups, a nice rule applies. The charge from IA to IIIA increases by the group and is positive. So any element in group IIA has 2 positive charges. Group IVA always has 4 charges. They can be positive or negative. After that they decrease by one from VA - VIIA and are always negative. V) 1. Which are the main trends to follow and understand in the Periodic Table of Elements? - Electronegativity, ionization energy, atomic radius 2. What is the relationship between electronegativity and polar bonds? - Electrons in a polar covalent bond are shifted toward the more electronegative atom; thus, the more electronegative atom is the one with the partial negative charge. The greater the difference in electronegativity, the more polarized the electron distribution and the larger the partial charges of the atoms. 3. Show with information available in the simulation the difference between polar and ionic bonds.

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Polar bonding is the unequal sharing of electrons between two different non metal atoms. Ionic bonding is the complete transfer of valence electron(s) between atoms. 4. Explain why the we need to add more energy to take away electrons with high electronegativity - Electronegativity is a property, it happens. So the tendency that high electronegativity elements is the attraction of a pair of electrons towards themselves. And the higher that attraction is, the more energy we have to apply to separate. Imagine trying to separate two strong magnets versus two weak magnets.

Discussion Properly understanding of the periodic table is very useful in the laboratory. Elements used everyday in the laboratory and in everyday life while performing experiments should be well known to us in order to better understand the reactions we see. The periodic table gives us, the viewer, a lot of information about the elements just by the way they are arranged. The periodic table arranges the chemical elements as a function of their properties. The vertical columns of the periodic table are called groups. The horizontal rows are called periods. There are 18 groups and 7 periods. Each element has a specific one or two letter symbol that is used interchangeably with its name. These symbols are often memorized. Most of the time, symbols are clearly referring to the name of the element they represent, like C represents carbon. However, sometimes an element's name and symbol have little relation. For example, the symbol for mercury is Hg. As you move across a period the atomic number increases. Similarly, as you move down a group the atomic number increases. In this way, the atomic number represents exactly where in the periodic table an element stands, more importantly, and the reason why the ordering of the elements according to atomic number is that it yields elements in groups with similar chemical and physical properties.

Conclusion The understanding of the periodic table and its properties such as atomic radius, ionization potential and electronegativity is very important in order to perform an efficient lab practice or experiment. It can give us so much information about the elements we already know, and it keeps being relevant since new elements that have been discovered when placed in the table following the rules the table has, they fit perfectly. Their characteristics match the ones of the families they are placed in as well. The simulation gave us several characteristics that were important and allowed us to compare different elements and a better understanding of where the characteristics place certain elements with the interactive activities such as differentiating between metals and non metals, and placing certain elements in their respective places.

References Herzog, G. F. (2020, June 02) Isotopes. Britannica. https://www.britannica.com/science/isotope Flowers, P., & Clark, A. (2020, October 27). Electronegativity and Polarity. Chemistry LibreTexts. https://chem.libretexts.org/Courses/Oregon_Institute_of_Technology/OIT %3A_CHE_202__General_Chemistry_II/Unit_6%3A_Molecular_Polarity/6.1%3A_Electronegativity_a nd_Polarity Lagowski, J. J. (2021, March 3). Periodic table- Britannica. https://www.britannica.com/science/periodic-table...