1. Atomic Structure Flashcards
Define the term isotope.
Isotopes are atoms of the same elements that have the same number of protons but different number of neutrons.
Nitrogen can form an ion which is isoelectronic with the fluoride ion.
Define the term isoelectronic.
Isoelectronic means that the two ions have the same number of electrons.
Nitrogen can form an ion which is isoelectronic with the fluoride ion.
The fluoride ion has 9 protons and 10 neutrons, state the electronic configuration of fluoride ion.
1s^2 2s^2 2p^6
Explain why the first ionisation energy of the fluoride ion is more than that of the nitrogen ion.
Nuclear charge of the fluoride ion is greater than in the ion of nitrogen while the screening effect is the same for both ions. Hence, more energy is required to overcome the stronger attraction between the outermost electron and the nucleus of the fluoride ion, causing first I.E. of fluoride ion to be greater.
s and p orbitals of different quantum numbers have the same shape, true/false?
True. s and p orbitals of different quantum numbers have the same shape but only different sizes.
A p orbital has higher energy of an s orbital of the same principal quantum number, true/false?
True. With the same principal quantum shell, a p orbital resides further away from the nucleus than an s orbital, hence it will have higher energy than an s orbital.
Each p orbital can only contain a maximum of 2 electrons, true/false?
True. All orbitals contain a maximum of 2 electrons.
Particle X has proton number, n.
Particle Y has proton number, n+1 and a charge of +2.
Particles X and Y are isoelectronic.
X has a charge of +1, true/false?
True. Since particle Y has a charge of +2, Y has electron number of n-1, since X and Y are isoelectronic, it must have an electron number of n-1 also.
Particle X has proton number, n.
Particle Y has proton number, n+1 and a charge of +2.
Particles X and Y are isoelectronic.
Y releases more energy than X when an electron is added to each particle, true/false?
True. Y has more protons than X, hence it has a higher nuclear charge, resulting in stronger attraction for electrons.
Particle X has proton number, n.
Particle Y has proton number, n+1 and a charge of +2.
Particles X and Y are isoelectronic.
Y has a smaller radius than X, true/false?
True. X and Y has the same number of electrons, Y has more protons than X hence it has higher nuclear charge and higher effective nuclear charge, resulting in a smaller radius.
Explain the difference between nuclear charge and effective nuclear charge.
Nuclear charge: Size of the positive charge, which is determined by the number of protons.
Effective nuclear charge: It is the strength of electrostatic forces of attraction felt by the valence electrons after taking into account the number of inner electrons.
Explain screening effect.
It is the decrease in electrostatic forces of attraction between the nucleus and the outermost electrons due to repelling effect of inner electrons.
Which of these statements incorrectly describe the outermost subshell of the phosphorus (group V) atom?
- It is half-filled with electrons
- It has a spherical shape
- The outermost subshell is a p orbital which has a dumb-bell shape.
Gaseous particle Y has n protons and a charge of +2.
Gaseous particle Z has (n-1) protons and is isoelectronic with Y.
Which of the following statements correctly describes Y and Z?
1. Y has a smaller radius than Z.
2. Y is less electronegative than Z.
3. Y has a higher first ionization energy than Z.
True
1. Gaseous particles Y and Z are isoelectronic i.e. have the same number of electrons. Since Y has n protons and Z has (n-1) protons, Y has a higher nuclear charge and higher effective nuclear charge resulting in a smaller radius.
3. Since proton/electron ratio is higher than in Y than Z, the electrons would be more tightly held in Y than Z.
False
2. Since the Y and Z are isoelectronic and Y has more protons than Z, Y can attract electrons to itself stronger than Z hence, it is more electronegative and the statement is false.
Why is the value of the 2nd I.E. greater than the 1st I.E. value?
After the 1st electron is removed, nuclear charge stays the same. However, the remaining electron is more strongly attracted to the nucleus, hence more energy is required to remove consequent electrons.
