Topic 2 All - Atomic Structure

What is the maximum number of electrons in the $4p$ subshell?

• A.$\hspace{1em}$ 6

• B.$\hspace{1em}$ 10

• C.$\hspace{1em}$ 2

• D.$\hspace{1em}$ 8

What is the electron configuration of this orbital diagram?

• A.$\hspace{1em}$ $\ce{1s^2 2s^2 2p^3}$

• B.$\hspace{1em}$ $\ce{1s^2 2p^3 2s^2}$

• C.$\hspace{1em}$ $\ce{1s^2 2s^3 2p^2}$

• D.$\hspace{1em}$ $\ce{1s^2 2s^2 3s^3}$

Which of the following subshells contains the highest energy?

• A.$\hspace{1em}$ $2s$

• B.$\hspace{1em}$ $2p$

• C.$\hspace{1em}$ $2d$

• D.$\hspace{1em}$ $3d$

The atom of an element Q has an atomic number of 27 and a mass number of 60. Which of the following statements is true about the subatomic particles of the atom of element Q?

• I.$\hspace{1em}$	Atom of element Q has 27 electrons and 60 protons
  II.$\hspace{1em}$	Atom of element Q has 27 protons and 27 electrons
  III.$\hspace{1em}$	Atom of element Q has 27 electrons and 60 neutrons
  IV.$\hspace{1em}$	Atom of element Q has 27 protons and 33 neutrons

• A.$\hspace{1em}$ I and IV only

• B.$\hspace{1em}$II and IV only

• C.$\hspace{1em}$II and III only

• D.$\hspace{1em}$I and III only

Which of the following is most likely to be the diameter of a carbon nucleus, if the diameter of a particular carbon atom is measured as 140 pm?

• A.$\hspace{1em}$ 12 amu

• B.$\hspace{1em}$ 0.0012 mm

• C.$\hspace{1em}$ 0.001 nm

• D.$\hspace{1em}$ 0.005 pm

In Rutherford’s gold foil experiment, some alpha particles bounced back towards the source. Which of the following statements best explains this result?

• A.$\hspace{1em}$ The atom consists mainly of empty space.

• B.$\hspace{1em}$ The atom has a positively charged center.

• C.$\hspace{1em}$ The atom consists of negative particles around the center.

• D.$\hspace{1em}$ The atom has a neutrally charged core.

Which of the following statements is not true?

• I.$\hspace{1em}$	Electrons have greater mass than protons and neutrons
  II.$\hspace{1em}$	Protons and neutrons are in the nucleus
  III.$\hspace{1em}$	Protons and electrons are charged subatomic particles
  IV.$\hspace{1em}$	Electrons are located outside the nucleus

• A.$\hspace{1em}$I and III only

• B.$\hspace{1em}$II and IV only

• C.$\hspace{1em}$II only

• D.$\hspace{1em}$I only

What is the term for the region where there is the highest probability of finding an electron?

• A.$\hspace{1em}$ Orbital

• B.$\hspace{1em}$ Nucleus

• C.$\hspace{1em}$ Orbital diagram

• D.$\hspace{1em}$ Orbit

Which of the following is the correct electron configuration of a typical sodium ion?

• A.$\hspace{1em}$ $\ce{[Ne] 3s^1}$

• B.$\hspace{1em}$ $\ce{[Ne] 3s^2}$

• C.$\hspace{1em}$ $\ce{[Ne]}$

• D.$\hspace{1em}$ $\ce{[Ne] 2s^1}$

The nuclear symbol for an isotope of iodine is $\ce{^{125}_{53}I}$. Which of the following is correct?

A mass spectrometer was used to determine that the relative ratio by mass of N:O in a molecule containing nitrogen and oxygen is 7:16. What is the most likely molecule?

• A. $\hspace{1em}$ $\ce{NO}$

• B. $\hspace{1em}$ $\ce{NO2}$

• C. $\hspace{1em}$ $\ce{NO3}$

• D. $\hspace{1em}$ $\ce{N2O5}$

Which of the following is the correct orbital diagram for $\ce{Carbon}$?

• A.$\hspace{1em}$
  B.$\hspace{1em}$
  C.$\hspace{1em}$
  D.$\hspace{1em}$

Which of the following is not a physical property of an isotope of an element with fewer neutrons in its atom?

• A.$\hspace{1em}$ Lower mass

• B.$\hspace{1em}$ Faster rate of diffusion

• C.$\hspace{1em}$ Higher density

• D.$\hspace{1em}$ Lower melting and boiling points

[Maximum mark: 2]

Cobalt is an important cofactor that often inhibits enzyme activity involved in cellular respiration, such as catalase.

1. Using the complete electron configuration, determine the electron configuration of $\ce{Co^2+}.$ [1]
   

2. Draw the orbital diagram of the $\ce{3d}$ electrons of $\ce{Co}$. [1]
   

The isotopes of carbon $\ce{^{12}C}$ and $\ce{^{13}C}$:

• I.$\hspace{1em}$	have the same atomic number
  II.$\hspace{1em}$	have the same physical properties
  III.$\hspace{1em}$	have the same chemical properties

• A.$\hspace{1em}$I and III only

• B.$\hspace{1em}$I and II only

• C.$\hspace{1em}$II and III only

• D.$\hspace{1em}$I, II and III

How many electrons are there in $\ce{^{35}_{17}Cl^{1-}}$?

• A.$\hspace{1em}$ 17

• B.$\hspace{1em}$ 18

• C.$\hspace{1em}$ 35

• D.$\hspace{1em}$ 36

The following table shows the number of subatomic particles present in five species.

Species	Number of protons	Number of neutrons	Number of electrons
A	8	8	8
B	8	8	10
C	9	10	8
D	10	10	10
E	10	12	10

Which two species are isotopes of the same element?

• A.$\hspace{1em}$A and B

• B.$\hspace{1em}$B and C

• C.$\hspace{1em}$C and D

• D.$\hspace{1em}$D and E

[Maximum mark: 4]

Hydrogen exhibits two emission lines, $D1$ and $D2$. $D1$ has a wavelength of $656\, nm$ and $D2$ has a frequency of $6.17\times 10^{14}s^{-1}$.

1. Calculate the frequency of the $D1$ emission line of hydrogen. [1]
   

2. Calculate the wavelength of the $D2$ emission line of hydrogen. [1]
   

3. Compare the two emission lines, and using the Data Booklet, suggest which of the emission lines is most likely to be red. [2]
   

The following table shows the number of subatomic particles present in five species.

Species	Number of protons	Number of neutrons	Number of electrons
A	8	8	8
B	8	8	10
C	9	10	8
D	10	10	10
E	10	12	10

Which species are ions?

• A.$\hspace{1em}$A and B

• B.$\hspace{1em}$B and C

• C.$\hspace{1em}$C and D

• D.$\hspace{1em}$D and E

What will happen to the frequency of moving light particles if the wavelength is doubled, assuming the velocity is constant?

• A.$\hspace{1em}$ The frequency will be doubled

• B.$\hspace{1em}$ The frequency will decrease by half

• C.$\hspace{1em}$ The frequency will not be affected

• D.$\hspace{1em}$ The frequency will increase by four

Which of the following statement(s) is (are) true?

• I.$\enskip$ The emission spectra are produced from a release of energy of excited electrons
  II.$\,$ No two electrons in one atom have the same set of quantum numbers
  III. The electrons in an orbital must have an opposite spin

• A.$\hspace{1em}$ I only

• B.$\hspace{1em}$ II and III only

• C.$\hspace{1em}$ I and II only

• D.$\hspace{1em}$ I, II, and III

Mass spectrometry uses fast-moving electrons to ionize particles and determine the mass-to-charge ratio of an unknown compound.

1. Using the data booklet section 1 and 2, calculate the frequency of an electron with a wavelength of $1.68\, m.$ [1]
   

2. Calculate the wavelength of an electron with a frequency of $2.00 \times 10^8 \,s^{-1}$. [1]
   

3. State the effect of increasing the wavelength on frequency. [1]
   

Which of the following statements is incorrect?

• A.$\hspace{1em}$All ions contain electrons

• B.$\hspace{1em}$A few alpha particles deflected at large angles in Rutherford's Gold Foil experiment

• C.$\hspace{1em}$A mass spectrometer can tell us the number of isotopes an element has

• D.$\hspace{1em}$An atom can have more neutrons than protons

[Maximum mark: 5]

The atom of element X has a mass number of 127 and has 74 neutrons. The ion derived from X has 54 electrons.

1. Calculate the number of protons of element X. [1]
   

2. State the nuclear symbol of the ion formed (refer to the periodic table). [2]
   

3. An isotope of X has a mass number of 132. Determine the number of neutrons in its atom. [2]
   

The following is a hydrogen energy level diagram.

How many different emission lines are possible?

• A.$\hspace{1em}$1

• B.$\hspace{1em}$5

• C.$\hspace{1em}$15

• D.$\hspace{1em}$30

[Maximum mark: 8]

Deuterium is an isotope of hydrogen that contains one proton, one neutron, and one electron.

1. 1. Complete the following table. [2]
      
      

      	Protons	Neutrons	Electrons
      Relative charge
      Relative mass			~$\dfrac{1}{1836}$
      Location

      
      

   2. Using the following data, calculate the relative atomic mass of hydrogen correct to five decimal places, showing your work. [2]
      

      Isotope	Relative abundance
      Hydrogen-1	99.98%
      Deuterium	0.012%
      Hydrogen-3	0.008%

   
   

2. 1. Describe the emission spectrum of the hydrogen atom. [2]
      

   2. Outline the difference between a continuous spectrum and a line spectrum. [1]
      

   3. Suggest how your answer to (b)(i) shows that energy levels are quantized. [1]
      

[Maximum mark: 9]

Cobalt-60 is a radioactive isotope of the element cobalt that is used to treat thyroid cancer.

1. 1. State the full electron configuration of cobalt and chromium. [2]
      

   2. Explain what is special about the electron configuration of chromium. [1]
      

   3. State the atomic symbol notation for the cobalt-60 isotope. [1]
      

One atom of cobalt-60 undergoes beta decay, releasing an electron and energy with a frequency of $7.65\times10^{19} Hz$ to form nickel-60.

2. 1. Using section 1 of the data booklet, calculate the wavelength of energy released from beta decay. [1]
      

   2. Using section 3 (Section 5- 2025 Syllabus) of the data booklet and your answer to (b) (i), deduce the type of electromagnetic radiation emitted. [1]
      

3. 1. Define orbital. [1]
      

   2. Sketch the shapes of an s-orbital and a p-orbital. [2]
      

[Maximum mark: 5]

Each element contains a different arrangement of electrons, and these electron configurations can also be represented using orbital diagrams. Determine the identity of each element described below.

1. $\ce{1s^2 2s^2 2p^6 3s^2 3p^6 4s^1}$ [1]
   

2. $\ce{[Ne] 3s^2 3p^6}$ [1]
   

3. In Period $3$ with valence electrons of $\ce{3s^2}$ [1]
   

4. $\mbox{}$ [1]
   

5. An ion with +1 charge, with valence electrons of:
   $\mbox{}$ [1]
   

[Maximum mark: 5]

Complete the following table:

Nuclear Symbol	Number of protons	Number of neutrons	Number of electrons
$_{62}^{153}\textrm{Sm}$			62
	81	120
$_{26}^{56}\textrm{Fe}^{2+}$	26
$_{46}^{103}\textrm{Pd}$	46
	16	16	18

Which of the following pairs of terms describe the shape of an s orbital and the relative energy of a d orbital?

Which atoms' orbital diagram does this figure represent?

• A.$\hspace{1em}$ $\ce{C}$

• B.$\hspace{1em}$ $\ce{O}$

• C.$\hspace{1em}$ $\ce{N}$

• D.$\hspace{1em}$ $\ce{F}$

[Maximum mark: 7]

$\ce{^{63}_{}Cu}$ and $\ce{^{65}_{}Cu}$ are the two most abundant isotopes of copper.

1. 1. Define isotope. [1]
      

   2. Determine the correct numbers of subatomic particles to complete the following table. [1]
      

      	Copper-63	Copper-65
      Number of protons
      Number of electrons
      Number of neutrons

      
      

   3. Calculate the relative abundances of $\ce{^{63}_{}Cu}$ and $\ce{^{65}_{}Cu}$ using section 6 (Section 7- 2025 Syllabus) of the data booklet. [3]
      

2. Complete the orbital diagram for the valence electrons in a copper atom and a copper (II) ion. [2]
   

   

[Maximum mark: 3]

$\ce{Cu}$ is a transition metal commonly used in wires.

1. Determine the complete electron configuration of $\ce{Cu}$. [1]
   

2. State the condensed electron configuration of $\ce{Cu+}.$ [1]
   

3. Determine whether the electron configuration of $\ce{Cu}$ follows the usual rules of electron configuration. [1]
   

[Maximum mark: 4]

John is sitting on a beach on a warm summer evening watching the reddish sky ($\lambda=650\, nm$) while his brother, Eric, is playing with his laser beam with a frequency of $4.60 \times 10^{14}\,s^{-1}$.

1. Calculate the frequency of the radiation from the red sky. [1]
   

2. Calculate the wavelength of the laser beam of Eric. [1]
   

3. Compare the wavelength of the laser beam with the wavelength of the radiation of the red sky. [1]
   

4. Deduce the colour of the laser beam of Eric. [1]
   

What is the smallest amount of energy an electron can release?

• A. $\hspace{1em}$ 0.31 $eV$

• B. $\hspace{1em}$ 0.54 $eV$

• C. $\hspace{1em}$ 10.19 $eV$

• D. $\hspace{1em}$ 13.59 $eV$

[Maximum mark: 5]

Lithium is a low-density alkali metal that reacts vigorously with water.

1. Given the below data and referring to the periodic table, calculate the relative abundances of the isotopes of lithium. [3]
   

Isotope	Atomic Mass
$^{6}\textrm{Li}$	6.015
$^{7}\textrm{Li}$	7.016

2. State the definition of an isotope. [1]
   

3. Outline the concept of relative abundance. [1]
   

[Maximum mark: 5]

Element Y has 4 stable isotopes. The table below shows the relative abundance and atomic masses of these isotopes.

Isotope	Percent abundance	Atomic mass
1	1.40 %	203.97
2	24.10 %	205.97
3	22.10 %	206.98
4	52.40 %	207.98

1. Calculate the relative atomic mass of the element. [2]
   

2. Identify the element. [1]
   

3. The atom of the element can form an ion with a charge of 4+. Determine the number of electrons in the ion. [1]
   

4. Determine the nuclear symbol of another corresponding ion of element Y given the numbers of subatomic particles: electrons = 80; neutrons = 122. [1]
   

[Maximum mark: 10]

Copper(II) chloride can exist as an anhydrous solid or hydrate.

1. A $1.78\ g$ sample of copper(II) chloride hydrate was heated on a watch glass until the blue solid changed completely to brown, and the following data was recorded:

   Mass of watch glass ($g$)	$24.57 \pm 0.01$
   Mass of copper(II) chloride hydrate ($g$)	$1.78 \pm 0.01$
   Mass of anhydrous copper(II) chloride + watch glass (1st heating, 5 min)	$26.03 \pm 0.01$
   Mass of anhydrous copper(II) chloride + watch glass (2nd heating, 5 min)	$25.99 \pm 0.01$
   Mass of anhydrous copper(II) chloride + watch glass (3rd heating, 2 min)	$25.99 \pm 0.01$

   Suggest a reason why the sample was heated for a second 5 minute increment showing a mass change. [1]
   

2. Calculate the mass of anhydrous copper(II) chloride. Do not include the calculations of uncertainties in your work. [1]
   

3. Calculate the mass of water in the hydrated copper(II) chloride sample. Do not include the calculations of uncertainties in your work. [1]
   

4. Calculate the percent uncertainty on the mass of water in the copper(II) chloride sample. [2]
   

5. Determine the chemical formula for the copper(II) chloride hydrate from the experimental data. [3]
   

6. State the chemical name of the copper(II) chloride hydrate from this experiment. [1]
   

7. State the core electron configuration for copper. [1]
   

What is the relative atomic mass, $\ce{A_r}$, of an unknown element found in a meteorite with the isotopic abundance shown below?

Isoptope	Abundance%
$X - 39$	80.0
$X - 40$	1.00
$X - 41$	19.0

• A. $\hspace{1em}$ 39.00

• B. $\hspace{1em}$ 40.00

• C. $\hspace{1em}$ 39.39

• D. $\hspace{1em}$ 40.50

Which electron transition in the hydrogen atom emission spectrum emits radiation with the highest frequency?

• A. $\hspace{1em}$ $n=1\ \rightarrow\ n=7$

• B. $\hspace{1em}$ $n=7\ \rightarrow\ n=1$

• C. $\hspace{1em}$ $n=5\ \rightarrow\ n=2$

• D. $\hspace{1em}$ $n=4\ \rightarrow\ n=3$