The Nuclear Atom (HL IB Chemistry)

Using your knowledge of atomic structure, complete the table below for the particles found in an atom. 

The actual mass of protons, neutrons and electrons is given.

Calculate the mass, in g, of a nitrogen molecule.

Oxygen consists of three stable isotopes, oxygen-16, oxygen-17, and oxygen-18.

State the particles present in each isotope and outline what differences would be expected in the chemical reactivity of the three isotopes.

Suggest why some elements have several isotopes and others, like fluorine, have only one known isotope (known as monoisotopic elements).

Nitrous oxide is used as a sedative in dentistry and has the formula N₂O.
Different sources of N₂O contain different ratios of ¹⁴N and ¹⁵N.           

State the name of the instrument used to distinguish between ¹⁴N and ¹⁵N and outline two characteristic differences seen in the analysis of ¹⁴N and ¹⁵N.

A sample of nitrous oxide was enriched so that it contained 4% by mass of ¹⁵N. Calculate the relative molecular mass of the resulting nitrous oxide.

Predict and explain, giving two reasons, how the first ionization energy of ¹⁵N would be different to ¹⁴N.

An atom has twice as many protons, and twice as many neutrons, as an atom of ¹⁵N.

Determine the chemical symbol for this atom, including the mass number, and deduce the number of electrons.

A and B are different chemical elements, from different groups in the Periodic Table.

State why ^mA and ⁿA have identical chemical properties, but ^mA and ^pB have different chemical properties. 

Atoms are made up of three subatomic particles; protons, neutrons and electrons.

Calculate the mass of one atom of carbon in kg.

¹²C, ¹³C and ¹⁴C are all isotopes of carbon.

State the difference between these three isotopes in terms of subatomic particles.

Give the full electron configuration of the following atoms and ions.

i)        Zinc (II) ion, Zn²⁺

[1]

ii)       Copper (II) ion, Cu²⁺

[1]

Chlorine has two naturally occurring isotopes, ³⁵Cl with a mass of 34.969 and ³⁷Cl with a mass of 36.966. The relative atomic mass of Cl is 35.5. Calculate the percentage abundance of each isotope.

Predict whether the atomic radius of ³⁵Cl or ³⁷Cl would be the greater and give a reason for your answer. 

A sample of cerium, Ce, was analysed in a  mass spectrometer. The relative abundances of three of the four main isotopes that were identified are shown in the table below.

A sample of cerium, Ce, has four isotopes that have a known relative abundance. This sample has an A_r of 140.12.

Use the data from the table to calculate m, the mass number and the percentage abundance of isotope ^mCe.

A sample of element Z was extracted from a meteorite. The table shows the relative abundance of each isotope in a mass spectrum of this sample of Z. Calculate the relative atomic mass of Z and suggest an identity of Z. Give your answer to 1 d.p. 

A naturally occurring sample of the element boron, B, has two isotopes of mass 10 and 11, and a relative atomic mass of 10.8.

Calculate the relative abundances of both isotopes in the sample of boron, B.

Give the full electron configuration of the Cu⁺ ion. 

Calculate the percentage abundance of ⁶³Cu with a mass of 62.9296 and ⁶⁵Cu with a mass of 64.9278, when the average mass of the Cu isotope is 63.546. Give your answer to an appropriate number of significant figures.

Outline why the chlorine atom has a smaller atomic radius than the sulfur atom.

The mass spectrum of chlorine gas is shown.

 Outline the reason for the two peaks at m/z = 35 and 37.

Explain the presence and relative abundance of the peak at m/z = 74.