Chemistry What s the Chemistry Matter? What s the Matter? Describing Particular Particles MATERIALS copies of sorting grids, laminated copy of particle card Set A, laminated copy of particle card Set B, laminated copy of particle labels, laminated All matter can be broken down into pure substances. The smallest representative particles of pure substances can vary greatly in traits like size, mass, arrangement, and composition. Scientists must be judicious about applying accurate terminology when describing a particle to avoid confusion with terms that seem similar but are not interchangeable. PURPOSE In this activity, you will apply vocabulary related to pure substances to sort and classify types of particles. PROCEDURE PART I: UNDERSTANDING VOCABULARY Read the definitions provided. Use them to answer the questions for Part I in the Analysis section. atom The smallest particle still characterizing a chemical element. It consists of a nucleus of a positive charge (Z is the proton number) carrying almost all its mass (more than 99.9%) and Z electrons determining its size. chemical compound A pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. chemical element A pure chemical substance composed of atoms with the same number of protons in the atomic nucleus. ion An atomic or molecular particle having a net electric charge. 1
PROCEDURE (CONTINUED) PART II: OPEN SORT 1. Your teacher will provide you with the six particle cards labeled as Set A. 2. Sort the cards into two groups based on a rule that you determine. 3. Sort each of the two piles from Step 2 into two subgroups based on a new rule. You should now have four groups. It is acceptable for a particle to be by itself in a group. 4. Answer the questions in Part II of the Analysis section. When you are done, exchange the Set A cards with your teacher. You will receive five grids and six particle type labels. PART III: FINDING THE OVERLAP 1. Obtain the two 3 3 grids with the following particle characteristics in their center boxes: Only 1 nucleus present Only 1 TYPE of nucleus present 2. Overlap the shaded area of the two grids as shown in Figure 1. Notice that the center box, which describes a characteristic of a particle, remains visible. An overlap means that the characteristic in the center of the combined grids can each apply to a single particle. Use tape to keep the grids in place. The overlap in Figure 1 shows that a particle having Only 1 nucleus present can also be described as having Only 1 TYPE of nucleus present. Figure 1. Overlapping grids Only 1 nucleus present Only 1 TYPE of nucleus present 2
PROCEDURE (CONTINUED) 3. Use your notes to dentify the neutral particle from Set A that exemplifies the overlap in Figure 1. Draw the particle in the space provided in Part III, Question 1 of the Analysis. 4. Obtain the six particle type labels (Monatomic Element, Monatomic Element and Ion, Polyatomic Element, Polyatomic Element and Ion, Polyatomic Ion, Compound). Determine which label accurately represents the current overlap and place the label card in an overlapping square. 5. Find the Has an electrical charge grid. How does this grid overlap your current pair of grids? Remember, any overlap must represent two true statements for a single particle. To test this overlap ask yourself, Can a single particle be described as both (a) and (b)? If the answer is true, then the overlap works and you can tape down the grid. 6. Look at the five remaining labels. Determine which of the labels can be applied to your newly created overlap, and place the label in an appropriate square. 7. Find the >1 nucleus present grid. How can this grid overlap your current grid arrangement? Test each overlap by evaluating whether a single particle could have all the characteristics written in the overlapping grids. When you are ready, tape the grid in place. 8. Look at the four remaining labels. Determine which labels can now be applied to new overlaps, and place the label cards in the appropriate squares. 9. Find the >1 TYPE of nucleus present grid. Overlap the grid where appropriate with the other four grids. When you are ready, tape the grid in place. 10. At this point, you should be able to place the remaining labels. Note that not all overlaps are labeled, and no label is used twice. 11. Answer the questions in Part III of the Analysis section. 3
PROCEDURE (CONTINUED) PART IV: CLOSED SORT 1. Obtain the six Set A particle cards from your teacher. 2. Sort and place the six particle cards labeled Set A from Part II on the labeled overlapping of grids that accurately describes the particle. For example, the particle W is a Monatomic Element, so it should be placed over that label. Each card belongs in only one of the six labeled overlaps, and each labeled overlap will have at least one particle. 3. Obtain the rest of the particle cards labeled Set B and repeat this process. 4. Answer the questions from Part IV of the Analysis section. Table 1. Closed Sort NH 3 ammonia C 2 H 5 OH ethanol N 2 nitrogen NH 4 1+ ammonium ion H 2 hydrogen O 2 2 peroxide ion Ar argon Fe 3+ iron(iii) ion C 3 H 8 propane C carbon NaCl sodium chloride O 2 oxygen CO 3 2 CsCl CH 3 OCH 3 carbonate ion cesium chloride dimethyl ether CH 4 methane O 3 ozone CH 3 OH methanol W tungsten N 3 nitride ion H 2 O water 4
ANALYSIS PART I: UNDERSTANDING VOCABULARY 1. Consider the definition for an atom. The same variable, Z, is used for both proton number and number of electrons. Explain what this means about the electrical charge of an atom. 2. Consider the definition for chemical element. Cite the factor that determines the elemental identity of an atom, and give one specific example. 3. Consider the definitions for atom, ion, and chemical element. Justify which subatomic particle changes when an atom becomes an ion but stays the same chemical element. 5
ANALYSIS (CONTINUED) PART II: OPEN SORT 1. Describe the rule you used for sorting the set of particles into two groups. 2. Describe the rule you used for sorting each of the two primary groups into two subgroups. 3. Refer to your answers in Question 1 and Question 2. In the shaded boxes of Table 2, provide the descriptions for each group and subgroup you used. In each unshaded box, draw all particles from Set A that match the description for the group and subgroup that describe it. 4. Look at the particles in each box of Table 2. Describe a rule that would allow you to further divide the particles into new subgroups. 6
ANALYSIS (CONTINUED) Table 2. Open Sort Group 1 Group 2 Descriptions in shaded cells Drawings in unshaded cells Subgroup 2 Subgroup 1 7
ANALYSIS (CONTINUED) PART III: FINDING THE OVERLAP 1. Identify and draw the neutral particle from Set A that can be described by both characteristics overlapping in Figure 1. 2. Some overlapping squares did not get a unique label even though the overlap may be true for a particle. Answer the following questions as you consider why a unique label was not needed for some squares. a. All particles that contain only one nucleus can also be described by which other characteristic? b. All particles with electrical charge and containing more than one nucleus can be further classified by which two labels? State what determines which of the two labels is appropriate. c. All particles that contain more than one type of nucleus can also be described by which other characteristic? 8
ANALYSIS (CONTINUED) PART IV: CLOSED SORT 1. Read the definition provided and underline key words. molecule An electrically neutral entity consisting of more than one atom (n > 1), all of which are nonmetals. a. On the basis of this definition, which of the particles that you placed in the Compound overlap could not also be labeled as molecules? Why not? b. Other than the ones labeled Compound, identify and write the formulas for the particles that are also molecules. c. Name each of the diatomic molecules. What do you notice about the names of these particles? d. Based on your observations of the representation of diatomic particles, draw a diatomic fluorine particle next to diatomic iodine particle in the space provided. State how the two particles are different. 9
ANALYSIS (CONTINUED) 2. Name the two molecular compounds you think would have the same mass. Justify your claim. 3. Look at the particle cards that represent ethanol, methane, methanol, and propane. Methanol and ethanol are both alcohols, but methane and propane are not. What part of the molecule do they share that could be responsible for this classification? Draw the particle that you think would represent a molecule called propanol. 4. Consider the name for the ion of iron used in the sort. State what you think the Roman numeral notation indicates. 10
CONCLUSION QUESTIONS 1. If a sample of matter has only one type of particle, no matter the type of particle, it is considered a pure substance. If a sample of matter contains more than one pure substance, it is considered a mixture. Give three examples of pure substances in your daily life and three examples of mixtures in the matrix provided in Table 3. Pure substance Table 3. Pure Substances and Mixtures Solid Phase Liquid Phase Gas Phase Mixture 11
CONCLUSION QUESTIONS (CONTINUED) 2. Use specific particles from the activity to explain why each of the following statements is false. a. All molecules are compounds. b. All compounds are molecules. c. All elements are atoms. d. Compounds made up of ions are also ions. 3. Articulate the relationship between atoms, molecules, and ions. 12