1.5 Practice Problems#
Show \(A\) and \(Z\) information for all the major elements in Earth’s crust in the correct format.
Determine the numbers of protons, neutrons, and electrons in each of the following species: \(\ce{^{35}Cl}\), \(\ce{^{37}Cl}\), \(\ce{^{41}K}\), and \(\ce{^{12}C}\).
An atom has \(A=114\) and \(66\) neutrons in its nucleus. What element is it?
What is the atomic and molar mass of \(\ce{O}\) in Earth’s atmosphere? The stable isotopic composition of \(\ce{O}\) atoms is \(\pu{99.759 \%}\) \(\ce{^{16}O}\), \(\pu{0.037 \%}\) \(\ce{^{17}O}\) and \(\pu{0.204 \%}\) \(\ce{^{18}O}\).
How many moles of \(\ce{As}\)are there in \(\pu{6.50 g}\) of \(\ce{As}\)?
How many atoms are there in \(\pu{3.559e-6 mole}\) of \(\ce{Kr}\)?
How many atoms are there in \(\pu{30.1 g}\) of \(\ce{Mg}\)?
What mass of \(\ce{Hg}\) contains the same number of atoms as \(\pu{90.15 g}\) of \(\ce{Hg}\)?
Calculate molecular and formula masses for the following compounds: (i) citric acid (\(\ce{H3C6H5O7}\)), (ii) barium acetate (\(\ce{Ba(C2H3O2)2}\)), and (iii) caffeine molecule shown in Fig. 3.
Determine the percent composition by mass of (i) sodium bicarbonate (\(\ce{Na2CO3}\)), (ii) lithium carbonate (\(\ce{Li2CO3}\)), and (iii) kaolinite (\(\ce{Al2Si2O5(OH)4}\)).
How many orbitals are in a subshell designated by the quantum numbers \(n = 3, l = 2\)?
How many subshells are in the shell designated by \(n = 3\)?
What is the total number of orbitals in the shell designated by \(n = 4\)?
What is the minimum value of the principal quantum number for an orbital in which \(m_l = +2\)?
Write the electron configuration of the following elements: \(\ce{Ti, Cr, Fe, Hg, Si, Se, Ar}\).
Identify the element represented by the following electron configuration: \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^4\)
Write the abbreviated electron configuration of \(\ce{Ti, Cr, Fe, Hg, Si, Se, Ar}\) using the correct noble gas core.
What element is represented by the following electron configuration: \([\ce{Kr}] 5s^2 4d^{10} 5p^5\)?
Write Lewis dot symbols for (a) \(\ce{F-}\), (b) \(\ce{K+}\), and (c) \(\ce{S^2-}\) (sulfide). Hint: Write the Lewis dot symbol for each element first, then add or remove electrons to get the correct ionic form.
Is it possible to determine the group number of a main group atom by looking at the Lewis dot symbol of its common ion? Explain.
Show the Lewis structure of (i) \(\ce{C2H4}\) (ethylene), (ii) \(\ce{N2}\), and (iii) \(\ce{C2H2}\) (acetylene). (Hint: There is a double bond in ethylene and a triple bond in other two molecular structures.)
Name the following ionic compounds: (a) \(\ce{CaO}\), (b) \(\ce{Mg3N2}\), and (c) \(\ce{Fe2S3}\).
Deduce the formulas of the following ionic compounds: (a) mercury (II) chloride, (b) lead (II) bromide, and (c) potassium nitride.
Balance the following chemical reactions using an approach you find that works for you: