1.1. A sample of Cerium, Ce, was analysed in a Time of Flight (TOF) mass spectrometer. The relative abundances of three of the four main isotopes that were identified are shown in Table 1. 

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

Table 1

Use the data from Table 1 to calculate m, the mass number and the abundance of isotope ^mCe. 

1.2. A time of flight (TOF) mass spectrum for a sample of Cerium, Ce, was obtained. The sample analysed was ionised by electron impact.

Identify the ion of Cerium, Ce, in Table 1 with the shortest time of flight and justify your answer.

1.3. An ⁸⁶Sr⁺ ion travels through the TOF mass spectrometer with a kinetic energy of 1.921 x 10^-15 J. 

The ion takes 1.09 x 10^-5 s to reach the detector. 

Calculate the length of the flight tube in meters. Give your answer to 3 significant figures.

    KE = $\frac{1}{2}$mv²     v = $\frac{d}{t}$    L = 6.02 x 10²³

1.4. A ⁷⁹Se⁺ ion travels through the flight tube with an energy of 6.27 x 10^-16 J.

Calculate the velocity of the ion.