Skip to main content
Chemistry LibreTexts

2.E: Atoms, Molecules, and Ions- Homework

  1. Last updated
  2. Save as PDF
  • Page ID
    360576

    • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    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

    1. How many protons, neutrons and electrons are present in one atom of the following:
      1. 1H
      2. 2H
      3. 3H
      4. 79Br
      5. 81Br1-
      6. 262Bh
    2. What is the Atomic Weight of chlorine given that:
      • The exact mass of 35Cl is 34.9689 and the relative abundance is 75.53%
      • The exact mass of 37Cl is 36.9659 and the relative abundance is 24.47%
      • Is this the answer that you expected?
    3. 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
      • 96Ru 5.54% 95.907599
      • 98Ru 1.87% 97.905287
      • 99Ru 12.76% 98.9059389
      • 100Ru 12.60% 99.9042192
      • 101Ru 17.06% 100.9055819
      • 102Ru 31.55% 101.9043485
      • 104Ru 18.62% 103.905424
    4. For the following molecules; write the chemical formula.
      1. carbon dioxide
      2. iron (II) chloride
      3. dinitrogen pentoxide
      4. iron (III) sulfate
    5. Name the following compounds.
      1. KI
      2. CaF2
      3. Cu2SO4
      4. N2O
      5. LiOH
    6. Give the chemical formula (or atomic symbol) and charge for the following ions:
      1. sulfate
      2. sulfite
      3. nitrate
      4. chloride
      5. nitride
      6. acetate
      7. 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

    1. Write the symbol for each of the following ions:
      1. the ion with a 1+ charge, atomic number 55, and mass number 133
      2. the ion with atomic number 15, mass number 31, and a 3− charge

      (a) 133Cs+; (b) 31P3−

    2. Give the number of protons, electrons, and neutrons in neutral atoms of each of the following isotopes:
      1. \(\ce{^7_3Li}\)
      2. \(\ce{^{125}_{52}Te}\)
      (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)

    Figure A shows a carbon atom that forms two, separate double bonds with two oxygen atoms.

    (b)

    Figure B shows a hydrogen atom which forms a single bond with a carbon atom. The carbon atom forms a triple bond with another carbon atom. The second carbon atom forms a single bond with a hydrogen atom.

    (a) molecular CO2, empirical CO2; (b) molecular C2H2, 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:

    1. uranium
    2. bromine
    3. gold
    4. 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, NCl3, ICl, and PCl5.

    Ionic: KCl; Covalent: NCl3, ICl, PCl5

    2.7: Chemical Nomenclature

    Name the following compounds:

    1. CsCl
    2. BaO
    3. K2S

    (a) cesium chloride; (b) barium oxide; (c) potassium sulfide;

    Write the formulas of the following compounds:

    1. rubidium bromide
    2. magnesium selenide
    3. calcium chloride

    (a) RbBr; (b) MgSe; (c) CaCl2

    Write the formulas of the following compounds:

    1. chlorine dioxide
    2. dinitrogen tetraoxide
    3. potassium phosphide
    4. silver(I) sulfide

    (a) ClO2; (b) N2O4; (c) K3P; (d) Ag2S

    Each of the following compounds contains a metal that can exhibit more than one ionic charge. Name these compounds:

    1. Cr2O3
    2. FeCl2
    3. CrO3

    (a) chromium(III) oxide; (b) iron(II) chloride; (c) chromium(VI) oxide

     

    This page titled 2.E: Atoms, Molecules, and Ions- Homework is shared under a CC BY license and was authored, remixed, and/or curated by Scott Van Bramer.