Helpful information: (1) An alpha particle is a helium nucleus, (2) ● e = 1.6 x 10-1⁹ C, (3) ke = 9.0 x 10° N m² C-2, (4) 1nm = 1 × 10-⁹ m 1-An alpha particle lies on the x-axis, a distance of 1.0 nanometer from a proton (in this set-up, the alpha particle is at the origin while the proton is in the positive direction). Which of the following choices below represents the magnitude of the electric force on the alpha particle?

1.3H      Protons_____      Neutrons_____      Electrons_____

The mass defect for potassium-40 is: -___x10-28kg. (Give your answer with 3 sig digs and do not include units) Use mass of proton = 1.007276 u mass of neutron = 1.008665 u actual mass = 39.9687 u

How many half-lives must elapse until (a) 77% and (b) 99 % of a radioactive sample of atoms has decayed? Part A Express your answer using two significant figures. ΜΕ ΑΣΦ Submit Request Answer Part B Express your answer using two significant figures. ΕΕ ΑΣΦ ? ?

The following reaction shows the beta decay of a °H nucleus. H- He + e +v 3 1 Determine the total energy (in kev) released in this decay. kev

Nuclear Physics - Nuclear Structure Density= Nuclear Structure Z mass Volume radius r=r04¹/3 ro=1.2x10-¹5 m N A = Z+N 4 The radius r of a nucleus is given in the above figure. The volume of a nucleus is V = Proton 56 Fe nucleus has a total of 56 nucleons (protons + neutrons). The average mass of a nucleon is u = 1.66x10^-27 kg I whin ber Neutron A Z If this unknown nucleus has 60 neutrons, how many protons does it have? Enter a number rr³ (a)Calculate the radius of a 56 Fe nucleus. Write the radius in fm, 1 fm = 10-15 m. Keep 2 decimal places. Enter a number x10-¹5m, fm (b) Calculate the Denisity of a 56Fe nucleus.. Write the result in terms of 1017 kg/m³. Keep 2 decimal places. Enter a number x10¹7kg/m³ () (c) An unknown hacieus has twice the volume of 56Fe. What is the mass number A of this nucleus? Enter a number i

One method for determining the age of ancient objects is by radiocarbon dating. Natural processes convert nitrogen to Carbon-14, a radioactive isotope with a half-life of 5730 years. When they are alive, animals assimilate Carbon-14 through the food chain. When an animal dies, it stops replacing its carbon and the amount of Carbon-14 decays exponentially. (a) Suppose the minimum detectable amount is 0.1% of the initial amount. What is the maximum age of a fossil that we could date using Carbon-14? (b) Suppose we wanted to date a fossil that was potentially 70 million years old. A radioactive isotope with what half-life would be required?

Scientists can determine the age of ancient objects by the method of radiocarbon dating. The bombardment of the upper atmosphere by cosmic rays converts nitrogen to a radioactive isotope of carbon, 14C, with a half-life of about 5730 years. Vegetation absorbs carbon dioxide through the atmosphere and animal life assimilates ¹4C through food chains. When a plant or animal dies, it stops replacing its carbon and the amount of 14C begins to decrease through radioactive decay. Therefore the level of radioactivity must also decay exponentially. A parchment fragment was discovered that had about 75% as much 14C radioactivity as does plant material on earth today. Estimate the age of the parchment. (Round your answer to the nearest whole number.) yr Need Help? Watch It Additional Materials THER

Tritium, the hydrogen isotope of mass 3, has a half-life of 12.3 y. What fraction of the tritium atoms remains in a sample after 50.0 y?

A pure sample of a newly discovered radioactive isotope is discovered. It has a half-ife of S9 min. Determine how long until only 1/16 of the original amount remains,