I need help with these questions (Circled answer choices might not be right)

In a particular atom, the nucleon number is the total number of A. protons. B. neutrons. C. electrons. D protons and neutrons. radio-isotope has an activ8. A radioactive isotope has a half-life of five minutes. A particular nucleus of this isotope has not decayed within a time interval of five minutes. A correct statement about the next five minute interval is that this nucleus A. has a lower than 50 % chance of decaying. B. will certainly decay. C. has a 50 % chance of decaying. D. has a better than 50 % chance of decaying. Emission and absorption spectra provide evidence for A. the nuclear model of the atom. B. natural radioactivity. C. the existence of isotopes. D. the existence of atomic energy levels.activity. D. the existence of atomic energy levels. 238 10. The number of neutrons and the number of protons in a nucleus of an atom of the isotope of uranium 92 U are Neutrons Protons A. 92 146 B. 146 92 C. 238 92 92 238shown Photons of energy 0.9 ev are incident on a low-pressure vapour. The energy levels of the atoms 0ev M Emir means -1.6ev up -2.5eV Need .9 difference -3.9ev not to scale What energy transition will occur when a photon is emitted by the vapor? A. -3.9eV to -1.6e V B.-2.5 eV to -1.6 eV C. -1.6eV to -3.9eV D. into a nucleus of Thorium by emittingS. C. electrons. (D) protons and neutrons. A radio-isotope has an activity of 400 Bq and a half-life of 8 days. After 16 days the activity of the sample is A. 200 Bq. B 100 Bq. C. 50 Bq. D. 25 Dstudent pours into a cylindrical container Violent 14. The nuclia . A large volumecarbonated me Alls the container. The Blaproof foam to gamm time. 40- 35- 30- 25 foam height / cm 20 VOPEX 15 o Rustona A 10- un goslou 5 BESTA 80 100 OES 120 0 20 40 60 time / s a. Determine the time taken for the foam to drop to (i) half its initial height. (ii) a quarter of its initial height.d. Complete the following nuclear decay equation for the decay of He 6. (2 marks) 6 6 He Lit 0 e 3 2 e. Describe the changes that occur to the subatomic particles of the Helium nucleus to make this decay possible. Also indicate why an electron was created and not a positron. acnerally "He with [2 marks)