In this activity we created our own Periodic Tables. We were given cards with the names and properties of elements and then had to group the different elements together in a way that made sense and we were able to defend and discuss why they are where they are placed. Since elements on the Periodic Table are group into families that have the common or same properties that is what we created again in different types of groups.
Pre-Lab Questions 1.What is an element? An element is a pure substance that is made from a single type of atom. Elements are the building blocks for all the rest of the matter in the world. Some examples of elements are oxygen, iron, hydrogen and helium. Even though elements are all made from the same type of atoms, they can still come in different forms. Depending on their temperature they can be solid, liquid, or gas. They can also take different forms depending on how tightly the atoms are packed together. Scientists call these allotropes. One example of this is carbon. Depending on how carbon atoms fit together they can form diamond, coal, or graphite. There are three families of elements. Elements are group together because they may have the same type of properties. Noble Gases - Helium, neon, argon, krypton, xenon, and radon are all noble gases. They are unique in that the outer shell of their atoms is full of electrons. This means they don't react much with other elements. They are often used in signs as they glow in bright colors when an electrical current is passed through them. Alkali Metals - These elements have just 1 electron in the outer shell of their atom and are very reactive. Some examples are lithium, sodium, and potassium. Other groups include transition metals, nonmetals, halogens, alkali earth metals, actinides, and lanthanides. 2. What is the atomic mass of an element? It is the total number of protons plus the total number of neutrons in the atomic mass. (amu) Example: Oxygen has 8 protons and 8 neutrons=16 amu 3. What is the atomic number of an element? The number of protons that are in the nucleus. Each element has a different number that identifies how many protons are in one atom of that element. All hydrogen atoms and only hydrogen atomsFor example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have an atomic number of 1. All carbon atoms, and only carbon atoms, contain six protons and have an atomic number of 6. Oxygen atoms contain 8 protons and have an atomic number of 8. The atomic number of an element never changes, meaning that the number of protons in the nucleus of every atom in an element is always the same. 4. How many atoms of each element are present in molecules of the following compounds? a) HCl One atom of H and one atom of CL, so two atoms. b)H2O 2 Hydrogen and 1 Oxygen, so three atoms. Post-Lab Questions 1. How many groups or families of elements are in your table? There were a total of four groups in my table of elements that I recreated and constructed. 2. What criteria did you use to choose which group or family an element belongs to? We arranged our table in order of atomic mass going down and going from the left to right. 3. Is there a trend in atomic mass going across your table? Is there a trend in the atomic mass going from top to bottom? Our main point of our reconstructed Periodic Table was the trend of increasing atomic mass going down and across our table. 4.Are there any exceptions to these trends? If so, which elements break the trend. None of the elements we were given and slipped into the table broke the trend of ascending atomic mass. 5.Are there any holes or gaps in your arrangement? Each element that we had in our table found a place that correctly sat in the table without creating any gaps or holes in our table. Extension Questions: 1.After we added several other elements to our table after creating our idea of a new periodic table we were able to fit these additional other elements into our table with no problems. The table only changed by adding the elements and making each group larger and adding length to each line of elements. 2. Our table is very similar to a modern periodic table because we have elements with the same description grouped together and each line has element with an ascending atomic mass. 3. Why is iodine placed after tellurium on the periodic table if the atomic mass of tellurium is greater than that of iodine? The Periodic table is based on the number of protons in an element and Iodine has more protons than tellurium. 4.Mendeleev left the noble gases out of his periodic table for a very good reason: they were not known, and there were no known elements with similar properties which would lead him to suspect that they existed. 4.
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