NAME______________________ KEY_____________________________________________PERIOD_______________ MIDTERM REVIEW PACKET 1. Density: A. Determine the density of an object with a mass of 42 g and a volume of 7.0 ml. 42g / 7.0 mL = 6.0 g/mL B. Determine the volume of an object with a mass of 8.1 g and a density of 2.4 g/ml. 8.1 g/2.4g/mL = 3.38 mL 2. Safety: a. A student gets a chemical on his hands then eats a chocolate bar. After he finishes the bar, he licks the melted chocolate off of his fingers. What should he do? Tell teacher. Consult the MSDS sheet regarding poisoning information. Apologize to his teacher for being a fool. b. Your partner spills a test tube of acid on her hand and starts to become hysterical. What should you tell her to do? Calm down. Escort her to the sink to rinse her hand. Tell the teacher. c. When should safety glasses be worn? The entire time that the laboratory is going on, until your teacher tells you it is safe to remove them. d. Your partner lights a Bunsen burner without realizing that your big, droopy sleeve of your fuzzy sweater is very close. Your clothes immediately catch fire. What should you do? Stop. drop and roll to put out the fire. Or, use fire blanket. Tell teacher. Apologize to your teacher for neglecting to wear the appropriate atture for lab! 3. States of Matter: Complete the following table. STATE OF MATTER SHAPE VOLUME (fixed or (fixed or varied?) varied?) SOLID fixed fixed ENERGY RANK (1-most, 3least) 3 LIQUID varies fixed 2 GAS varies varies 1 DESCRIPTION OF PARTICLE MOVEMENT (rotation, vibration, translation) vibration, rotation, translation (when affected by outside force) vibration, rotation, translation vibration, rotation 4. What is the difference between weight and mass? Which is a more dependable measurement? Explain your answer. Mass is the amount of matter in an object, while weight is the measurement of the effect of gravity on that matter. Mass is more reliable, because it does not change with location 5. Complete the following table: DESCRIPTION / DEFINITION matter that is made up of a single type of particle SUBSTANCE EXAMPLE Neon atom Water molecules ELEMENT matter that is comprised of a single type of atom only hydrogen HOMOGENEOUS MIXTURE a mixture (combination of more than one type of particle) which is uniform in consistency and appearance a mixture (combination of more than one type of particle) which is NOT uniform in consistency and appearance coffee with cream and sugar matter that is made of particles that are comprised of more than one type of atom bonded together NaCl or NH3 HETEROGENEOUS MIXTURE COMPOUND beach sand 6. Properties and Changes: Identify the following terms as one of the four (4) choices listed below. PC – Physical Change CC – Chemical Change PP – Physical Property CP – Chemical Property 1. Mass 3. Bending 5. Freezing Point 7. Color 9. Rusting 11. Hardness 13. Cutting PP PC PP PP CC PP PC 2. Melting Point 4. Evaporation 6. Explosiveness 8. Condensing 10. Reactivity 12. Cooking 14. Density PP PC CP PC CP CC PP 7. Basic Definitions: Define the following terms. 1. Chemistry the study of matter, and the changes that it undergoes. 2. Mass the amount of matter in something. 3. Energy anything that can perform work 4. Scientific Theory a supported hypothesis which explains the reasoning for phenomena 5. Scientific Law this describes a pattern observed in nature 6. Hypothesis tentative explanation for an observation in nature that is testable. Can be in “if, then, because” format anything that has both mass and volume 7. Matter 8. Imagine that a lab group measures the density of a sample of water. Keep in mind that the accepted density of water is 1.00 g/ml. Create data for each of the scenarios below (pretend that the group collected data from 3 separate trials. Trial 1 Trial 2 Trial 3 1. Data that is both accurate 1.00 1.00 1.00 AND precise 2. Data that is just precise 0.50 0.50 0.50 but NOT accurate 3. Data that is neither precise 206 31 0.0002 NOR accurate 9. List 4 parts of Dalton’s Atomic Theory. Include his original statements and any changes that have been determined by advances in studying the atom. If no changes have been made to his original ideas, indicate this in the space provided. ORIGINAL THOUGHTS MODERN DAY IDEAS 1. All elements are composed of tiny indivisible particles that Today we know that atoms are divisible into protons, neutrons are called atoms. and electrons 2. Atoms of the same element are identical. The atoms of any one element are different from those of any other element. Today, we know that there are some differences between some particles of the same elements such as ions and isotopes 3. Atoms of different elements can combine with one another in simple whole number ratios to form compounds This aspect has stood the test of time 4. Chemical reactions can occur when atoms are separated, joined, or rearranged. However, atoms of one element are not changed into atoms of another by chemical reactions This actually can occur during nuclear fusion and fission. 10. Describe the discovery of the nucleus. By whom was it discovered and how? Rutherford –gold foil experiment. Rutherford shot positively charged alpha particles at a thing sheet of gold. Some passed through, others were deflected, and other ricocheted right back. The ones that bounced back or were deflected were interacting with the nucleus. 11. Draw, label and describe the modern day model of the atom. Be sure to include all regions and subatomic particles and the location of each. 12. Explain what information can be determined by the following: a. Atomic Number: the number of protons in the nucleus, and the number of electrons in a neutral atom b. Mass Number: the number of neutrons in an atom, as long as you know the atomic number c. Atomic Mass: the weighted average of the mass numbers of the different isotopes of an element 13. Complete the following table with the appropriate information. ELEMENT/SYMBOL ATOMIC MASS # #p+ #e# Carbon C Calcium Ca Aluminum Chlorine Cl Al #no Nuclear Symbol 6 13 6 6 7 13 20 40 20 20 20 40 13 27 13 13 14 27 17 37 17 17 20 37 14. What is the most important piece of information used to identify an element? number of protons, which is the identifying characteristic of an element. 6 C 20Ca 13Al 17Cl The atomic number, which tells you the 15. Fill in the table below with the indicated information regarding groups on the Periodic table. Group 1A 2A 3A 4A 5A 6A 7A 8A Name Alkali metals Alkali Earth Metals Boron Group Carbon Group Nitrogen Group Oxygen Group Halogens Noble Gases Number of Valence e- 1 2 3 4 5 6 7 8 Valance econfiguration s1 s2 s2 p1 s2 p2 s2 p3 s2 p4 s2 p5 s2 p6 loses 1 loses 2 loses 3 n/a gains 3 gains 2 gains 1 n/a +1 +2 +3 n/a -3 -2 -1 n/a cation cation cation anion anion anion # e- lost or gained Charge of ion (Cation or anion?) 16. Write both the ELECTRON CONFIGURATION and ORBITAL NOTATION for the following examples Element Electron Configuration Orbital Notation Neon 1s2 2s2 2p6 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 1s 2s 2p Nitrogen 1s2 2s2 2p3 ↑↓ 1s ↑↓ ↑ 2s Fluorine 1s2 2s2 2p5 ↑↓ 1s ↑↓ ↑↓ ↑↓ ↑_ 2s 2p Lithium 1s2 2s1 ↑↓ 1s ↑__ 2s ↑ ↑__ 2p 17. Rank the following in order from the smallest to the largest: atom, electron, nucleus, molecule, proton electron, proton, nucleus, atom, molecule 18. What is the difference between an ion and an atom? How AND why do atoms become ions? Atoms # of protons = # of electrons, so they are neutral. This is not true for ions. Atoms become ions by gaining or losing electrons, and they do they to achieve a full set of valence electrons, like a noble gas 19. Explain how an atom of magnesium is different from a magnesium ion. a. What charge does a magnesium ion make? +2 cation b. Why is this charge produced? Magnesium loses two electrons c. Does magnesium become a cation or an anion? cation d. Which is bigger, the Magnesium ATOM or the Magnesium ION. Explain why. magnesium atom is bigger; the ion has lost electrons, so it has lost and entire energy level AND the protons now outnumber the electrons 20. Explain how an atom of chlorine is different from a chlorine ion. a. What charge does a chlorine ion make? -1 anion b. Why is this charge produced? Chlorine gains one electron so that it will achieve a full outer energy level c. Does chlorine become a cation or an anion? anion d. Which is bigger, the Chlorine ATOM or the Chlorine ION. Explain why. chlorine ion is bigger; the ion has gained electrons, so its electrons now outnumber its protons. Electrons will also repel each other a spread out. 21. A. What is an isotope? This is an atom of a given element that differs in the number of neutrons B. What two bits of information must be known in order to calculate the average atomic mass for an element? The mass numbers of the isotopes, and the percent abundance of each C. Use the following information to calculate the average atomic mass for the element Copper. Cu-63, 69.1% abundance Cu-65, 30.9% abundance (63 x 0.691 ) + (65 x 0.309) = 43.533 + 20.085 = 63.6 amu 22. What charge will the following ions make? 1. F -1 2. All group 3 elements +3 3. Na +1 4. An atom that loses 2e- +2 5. An atom that gains 1e- -1 -3 7. All group 6 elements -2 9. An atom with an electron configuration of 1s22s22p63s2 +2 6. An atom with 5 valence electrons 8. An atom with 2 e- in its outermost energy level 10. All alkaline earth metals +2 +1 23. Write the formula for the following compounds on the first line. Indicate whether each compound is ionic (I) or covalent (C) on the second, shorter line. a. Calcium nitrate __Ca(NO3)2__, __I___ b. Lithium nitride _______Li3N________, __I___ c. Tin (IV) chloride ____SnCl4__, __I__ d. Trinitrogen tetroxide ___N2O4________, ___C__ e. Sulfur dioxide ____SO2_____, __C___ f. Aluminum hydroxide ___Al(OH)3_____, _I____ 24. Name the following compounds. Indicate whether each compound is ionic (I) or covalent (C) on the second, shorter line. a. S3F6 ____Trisulfur hexafluoride, __C___ b. Na2SO4 _Sodium sulfate, ___I__ c. P2O5 _____Diphosphorus pentoxide, ___C__ d. Al2O3 _Aluminum oxide, __I___ e. Ca3(PO4)2 ___Calcium phosphate, __I___ f. Fe2O3 ___Iron (III) oxide, ___I__ 25. Fill in the table concerning properties of ionic vs. covalent compounds. Type of Compound General Characteristics Formed by metals, nonmetals or both? Ionic Compounds high boiling points and melting points, crystals, solids, metals and non-metals electrolytes Covalent Compounds can be solid, liquid or gas, non-metals and other insulators, brittle, nonnon-metals electrolytes Reason for characteristics ionic bonds form network solids, where each ion is bound to many others while the bonds within molecules are strong, the attractions between molecules may only be slight 50. What is the molar mass of: a. NaCN [Na (1 x 22.990g) + C (1 x 12.011g) + N (1 x 14.007g)] = 49.008g/mol b. Na2SO4 [Na (2 x 22.990g) + S (1 x 32.065g) + O (4 x 15.999)] = 142.041g/mol c. Al(C2H3O2)3 [Al (1 x 26.982g) + C (6 x 12.011g) + H (3 x 1.0079g) + O (6 x 15.999)] = 198.0657g/mol