A proton has positive charge of 1, that is, equal but opposite to the charge of an electron. A neutron, like the name implies, is neutral with no net charge. The charge is believed to be from the charge of the quarks that make up the nucleons (protons and neutrons).
Since you are referring to the TI-203 and TI-205, you need to know the actual masses of these two isotopes. TI-203 has 202.9723 amu and TI-205 has 204.9744 amu. Since you are concluding that this Thallium have 29.5% (Ti-203) and 70.5% (Ti-205), you need to multiply the percentage to the actual masses of the isotopes. With that, you should be able to get 204.3833 amu
Conductors are substances that pass an electrical charge.
Semiconductors are substances whose electrical conductivity is lower than that of metals and greater than that of dielectrics.
Electricity nonconductors or insulators - in the terminology of Faraday - dielectrics (see). N. perfect does not exist; they represent only a large resistance to galvanic current and then different bodies in varying degrees (see Galvanic current), so that between poor and good conductors there are many bodies of average conductivity. N. The galvanic current is also the best insulators of static electricity. N. Heat or its bad conductors are at the same time electrical insulators (see Thermal Conductivity).
A dielectric (insulator) is a substance that is poorly conducting or not conducting at all. The concentration of free charge carriers in a dielectric does not exceed 108 cm-3. The main property of the dielectric is the ability to polarize in an external electric field. From the point of view of the band theory of a solid body, a dielectric is a substance with a band gap greater than 3 eV.
The rule is always the same. Your final answer must have the same number of significant figures as the least accurate value in the calculation (one with the least number of significant figures) I hope this makes sense
