Modern Physics

Which of the following particles has mass?

• gluon

• quark

• photon

• W boson

Which of the following is part of the reason why stable heavy nuclei typically have more neutrons than protons?

• The neutrons negate the charges of some protons and thus reduce the net electric repulsion between protons.

• The neutrons increase the radius of the nucleus, which makes the protons further apart and decreases the electric repulsion between protons.

• The neutrons allow the strong force between nucleons to be great enough to counteract the electric repulsion between protons.

• The neutrons are arranged on the outside surface of the nucleus and shield the protons from external electric forces.

What is the common characteristic of most nuclei with mass number greater than about 20?

• binding energy per nucleon

• binding energy

• decay pattern

• half-life

Tags

NGSS.HS-PS1-8

In a nuclear decay chain, a neptunium nucleus eventually becomes a thallium nucleus via a series of alpha and beta minus decays. The net reaction is shown. Which of the following is true of the number of alpha and beta particles produced?

• More alpha particles than beta particles are produced.

• More beta particles than alpha particles are produced.

• An equal number of alpha and beta particles are produced.

• There is no way to determine whether more alpha or beta particles are produced without knowing the individual steps in the process.

Tags

NGSS.HS-PS1-8

In a laboratory, two protons are projected toward each other with the same speed, as shown. Which of the following best shows the paths of the protons as they approach and then move away from each other?

• 
• 
• 
• 

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

When a californium (Cf) nucleus undergoes spontaneous fission, the following two reactions occur, where X and Y are unidentified nuclei.

• Cf

• X

• Ru

• Y

Tags

NGSS.HS-PS1-8

A molybdenum isotope (Z=42) undergoes beta negative decay (β−). Based upon conservation of charge, what must be the atomic number (Z) of the product? Also, what particles decay and what particles are produced during β− decay?

• Z=41; in β− decay, a neutron transforms into a proton, releasing an electron and a chargeless antineutrino.

• Z=41; in β− decay, a proton transforms into a neutron, releasing an electron and a chargeless antineutrino.

•  Z equals 43 ; in β− decay, a neutron transforms into a proton, releasing an electron and a chargeless antineutrino

• Z=43; in β− decay, a proton transforms into a neutron, releasing an electron and a chargeless antineutrino.

Tags

NGSS.HS-PS1-8

An unstable atom of radium (atomic mass = 226u) is initially at rest. It decays into radon (atomic mass = 222u) and an alpha particle (atomic mass = 4u). After the decay, the alpha particle travels with a speed that is 10% the speed of light. What is the speed at which radon travels after the decay process?

• 0.00177c

• 0.00180c

•  0.09823c

• 0.10180c

Tags

NGSS.HS-PS1-8

NGSS.HS-PS3-1