IB Chemistry Topic S1.3 Electron Configurations Questionbank (SL/HL)

Question 1

HLPaper 2

The elements sodium and magnesium are located in Period 3 of the periodic table and show predictable patterns in electron arrangement.

1.

Write the electron configuration of sodium ( $Z = 11$ ) and magnesium ( $Z = 12$ ).

[1]

2.

Deduce the number of core and valence electrons in each atom.

[2]

3.

State and explain which atom has a higher first ionization energy.

[2]

4.

Magnesium can also form a $M g^{2 +}$ ion. Explain how its electron configuration changes and why this ion is stable.

[2]

Question 2

HLPaper 1A

Which element has the following ground-state electron configuration: $[Ar] 4 s^{1} 3 d^{5}$ ?

Question 3

SL & HLPaper 1A

Which atom has the electron configuration $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{4}$ ?

Question 4

SL & HLPaper 1A

Which of the following elements has three unpaired electrons in its ground-state configuration?

Question 5

SL & HLPaper 1A

What is the number of valence electrons in a nitrogen atom ( $Z = 7$ )?

IB Chemistry S1.3 Electron Configurations Questionbank