Answer:
1. The charge of one mole of Mg^2+ ion can be determined by considering the charge of a single Mg^2+ ion. The charge of an electron is -1.602 * 10^-19 C, and since the Mg^2+ ion has a charge of +2, it means that it has lost two electrons. Therefore, the charge of one mole of Mg^2+ ions would be 2 * (1.602 * 10^-19 C) = 3.204 * 10^-19 C.
Among the given options, the closest answer is (d) 3 * (1.602 * 10^-19 C), which is approximately 4.806 * 10^-19 C. While not the exact value, it is the closest approximation.
2. The e\/m value represents the charge-to-mass ratio of a particle. To determine the highest e/m value, we need to consider the charge and mass of each particle:
- α particle (helium nucleus) consists of two protons and two neutrons, with a charge of +2e (double the charge of a proton) and a mass of 4 amu (atomic mass unit). Therefore, its e\
/m value is (2e)/(4 amu).
- β particle (electron) has a charge of -e and a relatively small mass compared to other particles. So its e\/m value is (-e)/(mass).
- Mg^2+ ion has a charge of +2e and a larger mass than an electron. So its e/m value is (2e)/(mass).
- Na+ ion has a charge of +e and a larger mass than an electron. So its e/m value is (e)/(mass).
- Positive ray particle (proton) has a charge of +e and a mass similar to that of a neutron. So its e/m value is (e)/(mass).
From the given options, the highest e/m value is exhibited by the β particle (electron) because it has the smallest mass compared to the other particles, resulting in a larger charge-to-mass ratio. Therefore, the answer is (b) β particle.