Chem PLQ questions - Exam 1 Questions With 100% Correct Answers.

A set of measurements that are accurate always means that _______ - their average is close to the true value. Choose all of the following that have a positive charge. anions cations atoms protons neutrons electrons - cations, protons Consider the species 72Zn, 76Se, and 73Ga. These species have: - the same number of neutrons Dr. Kerr can choose to cover fewer chapters (less material) if she wanted to for this course. - False How many columns on the periodic table belong to Main Group elements? Enter the number of columns (only) below. - 8 How many pounds are in 4.907 x 108 micrograms? 1 kg = 2.20462 pounds Enter ONLY the number (no units) below to 3 decimal places. - 1.082 How many protons, neutrons, and electrons does the follow have? 55/25 Mn+7 - protons= 25 neutrons= 30electrons= 18 How many significant digits are in the number: 40800? - 3 How many significant figures are in the number: 0. In olden times, apothecaries used to dispense medicine using their own system of measurements that are listed below. Use the conversions below (and dimensional analysis) to determine how many milligrams would be in a sample of 1.250 scruples. Hint: You will have to convert kg to mg using the conversions you have memorized. 1 apothecary pound = 12 ounces 1 ounce = 8 drams 3 scruples = 1 dram 1.2153 apothecary pound = 1 English pound 1 kg = 2.205 English pounds Enter your answer to 4 significant digits. Do not include the units. - 1,620 In the formula unit: Ba3(PO4)2 how atoms many of each element are there? - Ba- 3, P- 2, O- 8 Match the element with its correct symbol. Argon Arsenic Tin Antimony Scandium Strontium - Ar, As, Sn, Sb, Sc, SrSelect all of the following that are chemical changes. -water melting -iron rusting -salt dissolving in water -wood burning -frying an egg - -iron rusting -wood burning -frying an egg The following measurements of the mass of an object were made by different people in a lab. Each set gives the results of three measurements followed by the average. Which set is the most precise? All values are in grams. The standard value of the object's mass reported by an analytical laboratory was 1.501 g. A.) 1.513, 1.503, 1.522 avg= 1.513 B.) 1.513, 1.511, 1.450 avg= 1.491 C.) 1.513, 1.459, 1.533 avg= 1.502 D.) 1.513, 1.517, 1.512 avg= 1.514 E.) 1.513, 1.510, 1.523 avg= 1.515 - D.) 1.513, 1.517, 1.512 avg= 1.514 The neutral atoms of all of the isotopes of the same element have: - the same number of electrons There are make up exams in this CHEM 1314 course. - False True or False: A student that has earned 75% on the PLQs, and iClicker questions would actually earn 100% for both of these grade items. - TrueTrue or False: Canvas is great at calculating overall grades. - False Two metal samples with the same volumes were weighed. One sample was iron and the other was copper. The two masses that were measured were 17.92 g and 15.74 g. Which mass corresponds to the copper sample, and which to the iron sample?What is the volume of both metals? Element: Iron/ Copper Density: 7.87 g/cm3/ 8.96 g/cm3 - Mass of Cu: 17.92 Mass of Fe: 15.74 Volume of both metals: 2.00 cubic centimeters What are the number of hours that students are expected to spend on this course outside of class and lab according to the 'Participation Expectations' part of the syllabus? - 8