The Nucleus – Flashcards

A scientist is trying to determine whether a certain substance is radioactive. Which question would be most helpful to ask? a. Does the substance have a positive electric charge or a negative electric charge? b. Can the substance be used to generate electricity in a power plant? c. Do the atoms that make up the substance have nuclei that split apart over time? d. Do the nuclei of the substance's atoms contain more neutrons than protons?

Many radioactive atoms that have large masses undergo radioactive decay by releasing a particle that is identical to a helium-4 nucleus. What changes in the original atom are expected as a result of this natural phenomenon? a. The atomic number and the mass number will decrease. b. The atomic number and the mass number will increase. c. The atomic number will increase, and the mass number will decrease. d. The atomic number will decrease, and the mass number will increase.

How are energy and mass connected during the formation of an atom? Energy is absorbed, so the mass is increased. Energy is released, so the mass is increased. Energy is absorbed, so the mass is reduced. Energy is released, so the mass is reduced.

Which answer choice best explains why uranium-238 can be used in power plants to generate electricity? Nuclides of uranium-238 decay over time. They release large amounts of energy as their nuclei break apart. Nuclides of uranium-238 are extremely stable. They can absorb large amounts of energy without breaking apart, so they rarely need to be replaced. Because atoms of uranium-238 have many more electrons than protons, they release steady streams of electric current. Because atoms of uranium-238 have many more protons than neutrons, they attract large numbers of electrons from the surrounding environment.

These statements describe three different reactions. 1 - An atom shares electrons with another atom. 2 - The nucleus of an atom is split apart. 3 - An atom gains an electron from another atom. Which reaction(s) most likely release the greatest amount of energy? 1 2 1 and 3 2 and 3

Which answer choice best explains why nuclear reactions release more energy than chemical reactions? a. Electrostatic forces of repulsion are thousands of times stronger than gravitational forces. b. Gravitational forces are thousands of times stronger than electrostatic forces of repulsion. c. The force that binds together protons and neutrons is stronger than the force that attracts and repels protons and electrons. d. The force that attracts and repels protons and electrons is stronger than the force that binds together protons and neutrons.

The nuclei of most atoms contain multiple protons. Each proton has a positive charge. If objects that have like charges repel each other, why do the protons in the nuclei of most atoms not fly apart? a. The charges of protons and neutrons cancel each other out. b. Electrons outside the nucleus push on protons. c. A strong nuclear force between an atom's protons and neutrons holds together the atom's nucleus. d. Protons experience a more powerful attraction to the negatively charged particles in an atom's nucleus.

Which sequence is an example of radioactive decay? The nuclei of two hydrogen atoms fuse together, forming a helium nuclide. A calcium atom gives its electrons to two fluorine atoms, forming a formula unit of calcium fluoride. A polonium isotope becomes a lead isotope when the polonium nuclide emits two protons and two neutrons. Energy from an electric current splits a water molecule into two hydrogen atoms and one oxygen atom.

An example of a radioactive isotope is carbon-12. carbon-14. neon-20. neon-22.

In reaction A, each sodium atom gives one electron to a chlorine atom. In reaction B, an isotope of oxygen decays to form an isotope of nitrogen. Which statement best describes the energy that is released per gram by these reactions? Reaction A releases more energy than reaction B releases. Reaction B releases more energy than reaction A releases. Reaction A and reaction B release equal amounts of energy. Neither reaction A nor reaction B releases energy.

Which answer choice best explains why atoms of carbon-14 (C-14) are unstable? Atoms of C-14 have too many negatively charged electrons and too few positively charged protons. Atoms of C-14 have too many positively charged protons and too few negatively charged electrons. The attractive force that the protons in the nuclei of C-14 atoms generate is not strong enough to overcome the repulsive force that the neutrons generate. The attractive force that the neutrons in the nuclei of C-14 atoms generate is not strong enough to overcome the repulsive force that the protons generate.

Which statement illustrates the difference between a chemical reaction and a nuclear reaction? A nuclear reaction releases more energy per gram and appears to violate the law of conservation of mass. A nuclear reaction releases less energy per gram and appears to violate the law of conservation of mass. A nuclear reaction releases more energy per gram but does not appear to violate the law of conservation of mass. A nuclear reaction releases less energy per gram but does not appear to violate the law of conservation of mass.

What is the nuclear binding energy of an atom that has a mass defect of 5.0446 mc016-1.jpg 10-29 kg? Use E = mc2. (Remember: The speed of light is approximately 3.00 mc016-2.jpg 108 m/s.) 5.61 mc016-3.jpg 10-46 J 1.51 mc016-4.jpg 10-20 J 4.54 mc016-5.jpg 10-12 J 1.78 mc016-6.jpg 1045 J