2.E: Atoms, Molecules, and Ions- Homework
For Chapter 2 you MUST know:
- The names and symbols for elements 1-36
- Know the polyatomic Ions. You MUST know ammonium (\(\ce{NH4+}\)), acetate ( \(\ce{CH_3COO^-}\)), carbonate ( \(\ce{CO_3^{2-}}\)), hydroxide ( \(\ce{OH^-}\)), nitrate ( \(\ce{NO_3^-}\)), phosphate ( \(\ce{PO_4^{3-}}\)), and sulfate ( \(\ce{SO_4^{2-}}\)).
Turn in your answers for the following questions - show your work
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How many protons, neutrons and electrons are present in one atom of the following:
- 1 H
- 2 H
- 3 H
- 79 Br
- 81 Br 1 -
- 262 Bh
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What is the Atomic Weight of chlorine given that:
- The exact mass of 35 Cl is 34.9689 and the relative abundance is 75.53%
- The exact mass of 37 Cl is 36.9659 and the relative abundance is 24.47%
- Is this the answer that you expected?
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What is the Atomic Weight of ruthenium given the following information from WebElements, www.webelements.com. Is this the answer that you expected?
- Isotope Abundance Exact Mass
- 96 Ru 5.54% 95.907599
- 98 Ru 1.87% 97.905287
- 99 Ru 12.76% 98.9059389
- 100 Ru 12.60% 99.9042192
- 101 Ru 17.06% 100.9055819
- 102 Ru 31.55% 101.9043485
- 104 Ru 18.62% 103.905424
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For the following molecules; write the chemical formula.
- carbon dioxide
- iron (II) chloride
- dinitrogen pentoxide
- iron (III) sulfate
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Name the following compounds.
- KI
- CaF 2
- Cu 2 SO 4
- N 2 O
- LiOH
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Give the chemical formula (or atomic symbol) and charge for the following ions:
- sulfate
- sulfite
- nitrate
- chloride
- nitride
- acetate
- carbonate
The Following Questions are for your practice - Do Not Turn In. They include answers so you can check your work
2.3: Atomic Structure and Symbolism
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Write the symbol for each of the following ions:
- the ion with a 1+ charge, atomic number 55, and mass number 133
- the ion with atomic number 15, mass number 31, and a 3− charge
(a) 133 Cs + ; (b) 31 P 3 −
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Give the number of protons, electrons, and neutrons in neutral atoms of each of the following isotopes:
- \(\ce{^7_3Li}\)
- \(\ce{^{125}_{52}Te}\)
(a) 3 protons, 3 electrons, 4 neutrons; (b) 52 protons, 52 electrons, 73 neutrons
2.4: Chemical Formulas
Write the molecular and empirical formulas of the following compounds:
(a)
(b)
(a) molecular CO 2 , empirical CO 2 ; (b) molecular C 2 H 2 , empirical CH
2.5: The Periodic Table
Using the periodic table, classify each of the following elements as a metal or a nonmetal, and then further classify each as a main-group (representative) element, transition metal, or inner transition metal:
- uranium
- bromine
- gold
- americium
(a) metal, inner transition metal; (b) nonmetal, representative element; (c) metal, transition metal; (d) metal, inner transition metal
2.6: Molecular and Ionic Compounds
Using the periodic table, predict whether the following chlorides are ionic or covalent: KCl, NCl 3 , ICl, and PCl 5 .
Ionic: KCl; Covalent: NCl 3 , ICl, PCl 5
2.7: Chemical Nomenclature
Name the following compounds:
- CsCl
- BaO
- K 2 S
(a) cesium chloride; (b) barium oxide; (c) potassium sulfide;
Write the formulas of the following compounds:
- rubidium bromide
- magnesium selenide
- calcium chloride
(a) RbBr; (b) MgSe; (c) CaCl 2
Write the formulas of the following compounds:
- chlorine dioxide
- dinitrogen tetraoxide
- potassium phosphide
- silver(I) sulfide
(a) ClO 2 ; (b) N 2 O 4 ; (c) K 3 P; (d) Ag 2 S
Each of the following compounds contains a metal that can exhibit more than one ionic charge. Name these compounds:
- Cr 2 O 3
- FeCl 2
- CrO 3
(a) chromium(III) oxide; (b) iron(II) chloride; (c) chromium(VI) oxide