Physics: Chapter 34

In which of these processes is an element of matter changed into a completely different element?

C. both of these

Present-day research in nuclear fusion uses

C. both of these

Three isotopes that undergo nuclear fission are

D. U-233, U-235, U-239

When uranium-238 absorbs a neutron, it

becomes a beta emitter

In the fissioning of uranium, a chain reaction is caused by

ejected neutrons

Compared to the mass of a uranium nucleus before splitting, the pieces it splits into have

less mass

In a nuclear fission and nuclear fusion reactions, the amount of mass converted to energy of other forms is

less than 1%

The most abundant element in the universe is

A. hydrogen

When two light atoms fuse together, mass

A. is converted to kinetic energy of neutrons

Energy released by the suns results from the process where in atomic nuclei

B. combine

A nuclear process that has relatively few radioactive by-products is

B. fusion

In both fission and fusion, mass

B. is converted to kinetic energy

Electrical forces inside a nucleus contribute nuclear

Instability

the effect of putting small amounts of PU-239 with U-238 is converting U-238 to

Pu-239

Control is exercised in a nuclear reactor by

absorbing excess neutrons with control rods

A chain reaction grows when the average number of liberated neutrons that go on to cause further fission is

greater than one

when a lumo of uranium is broken into smaller pieces, the total surface area of the lump

increases

Uranium-235, uranium-238 and uranium-239 are different

isotopes

When neptunium emits a beta particle the result is

plutonium

In a breeder reactor

uranium is converted into plutonium