2437

Physics Modern Physics Level: High School

Radioactivity

A particle radioisotope has a half-life of 23.4 hours . At time t = 0, the activity is 6.90 x 10^9 Bq . Calculate the following .

a) The activity when t = 23.4 hours .

b) The time when activity will be reduced by a factor of 100 .

c) The value of the decay constant .

d) The original number of radioactive nuclei .

e) The number of radioactive nuclei at t = 23.4 hours .




2436

Physics Modern Physics Level: High School

Dual Nature

An incident x ray is Compton scattered by a free electron at an angle of 35 degree . A high purity germanium detector is used to detect the scattered x-ray . The detector indicates that the energy of the scattered x ray is 65 keV . What is the energy of the incident x-ray ?



2435

Physics Modern Physics Level: High School

Bohr's Atomic Model

A hydrogen atom is in the fifth excited state when it emits a photon with a wavelength of 1090 nm . Note than n = 2 is the first excited state . Calculate the energy of the atom in the final state .




2431

Physics Modern Physics Level: High School

Radioactivity

How much time is required before a 10 mCi sample of 99mTc (t ½ = 6.0 hours) and a 25 mCi sample of 113m In (t ½ = 1.7 hours ) possess equal activities ?



2111

Physics Modern Physics Level: High School

Nucleus

The half-life of carbon-14 is 5730 years . The time for ¾ of a sample of carbon-14 to decay is

a) 350 years

b) 2865 years

c) 11460 years

d) 17190 years

e) none of the above




2110

Physics Modern Physics Level: High School

Nucleus

The mass of an atom of helium-4(Z=2) is less than the mass of two free protons and two free neutrons because of ?

a) nuclear fusion

b) nuclear fission

c) neutron

d) nuclear emission

e) binding energy

e) binding energy



2109

Physics Modern Physics Level: High School

Nucleus

When radium-223 (Z=88) decays to radon-219 (Z=86) , the other particle emitted is a(n)

a) alpha particle

b) beta particle

c) gamma ray

d) x-ray

e) none of the above




2108

Physics Modern Physics Level: High School

Nucleus

Radioactive decay is involved in which of the following ?

a) Keeping of the Earth’s interior hot

b) Making smoke detectors work

c) Supplying energy for interplanetary space

d) Making the sun shine

b) Making smoke detectors work



2107

Physics Modern Physics Level: High School

Nucleus

How do isotopes of a given element differ ?

a) They have different mass numbers

b) They have different electron numbers

c) They have different atomic numbers

d) They have different quantum

e) None of the above

a) They have different mass numbers



2106

Physics Modern Physics Level: High School

The continuous part of an x-ray spectrum of an atom occurs because

a) of the photon absorption

b) of the photoelectric effect

c) electrons in the atom make transitions to lower energy

d) of the uncertainty principle

e) of rapid deceleration of the bombarding electrons

c) electrons in the atom make transitions to lower energy



2105

Physics Modern Physics Level: High School

Photoelectric effect

When the frequency of light is decreased in a photoelectric effect , the energy of the emitted electrons

a) increase

b) decrease

c) stays the same

d) becomes more quantized

e) become less quantized




2104

Physics Modern Physics Level: High School

Atom

The highest energy level in an atom is its

a) ionization level

b) emission level

c) absorption level

d) photon level

e) ground state

a) ionization level



2103

Physics Modern Physics Level: High School

Duel nature

The fact that a particly cannot be precisely localized is the ?

a) photoelectric effect

b) uncertainty principle

c) principle of a hologram

d) principle of a laser

b) uncertainty principle



2102

Physics Modern Physics Level: High School

Atom

An excited atom gains energy by ?

a) emitting a photon

b) absorbing a photon

c) undergoing a photoelectric effect

d) increasing its de Broglie wavelength

e) the uncertainty principle

b) absorbing a photon

Displaying 136-149 of 149 results.