1- BNCT relies on the initial targeting of tumor cells by an appropriate chemical compound tagged with 10 5 B , which preferentially concentrates in tumor cells. During the irradiation of the tumor site by neutrons ( 1 0 n ) the 10 5 B absorbs a low-energy neutron ( 1 0 n ), and it ejects an energetic short-range alpha particle ( 4 2 α or 4 2 He ) and lithium ion along with gamma radiation (γ ). This radiation deposits most of its energy within the cell containing the original 10 5 B atom. Therefore, if a higher concentration of 10 5 B exists in tumor cells relative to other normal tissues, a concomitantly higher dose will be delivered to the tumor cells during neutron irradiation.What is the nuclear reaction that takes place in the tumor cell?Express your answer as a nuclear equation.

2- Calculate the mass defect of the fluorine nucleus 19/ 9 F . The mass of neutral 19 / 9 F is equal to 18.998403 atomic mass units.Express your answer in atomic mass units to four significant figures.

3- Calculate the binding energy E B of the fluorine nucleus 19 / 9 F .Express your answer in millions of electron volts to four significant figures.

4-234/ 90 Th undergoes beta decay. What is the atomic number of the resulting element?Express your answer numerically as an integer.

5-What is the value of A in the following nuclear reaction?
237 / 93 Np→ 233 / 91 Pa+ A/ Z X
Express your answer as an integer.