# 21.4 Transmutation and nuclear energy  (Page 4/26)

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An atomic bomb ( [link] ) contains several pounds of fissionable material, ${}_{\phantom{\rule{0.5em}{0ex}}92}^{235}\text{U}$ or ${}_{\phantom{\rule{0.5em}{0ex}}94}^{239}\text{Pu},$ a source of neutrons, and an explosive device for compressing it quickly into a small volume. When fissionable material is in small pieces, the proportion of neutrons that escape through the relatively large surface area is great, and a chain reaction does not take place. When the small pieces of fissionable material are brought together quickly to form a body with a mass larger than the critical mass, the relative number of escaping neutrons decreases, and a chain reaction and explosion result.

## Fission reactors

Chain reactions of fissionable materials can be controlled and sustained without an explosion in a nuclear reactor    ( [link] ). Any nuclear reactor that produces power via the fission of uranium or plutonium by bombardment with neutrons must have at least five components: nuclear fuel consisting of fissionable material, a nuclear moderator, reactor coolant, control rods, and a shield and containment system. We will discuss these components in greater detail later in the section. The reactor works by separating the fissionable nuclear material such that a critical mass cannot be formed, controlling both the flux and absorption of neutrons to allow shutting down the fission reactions. In a nuclear reactor used for the production of electricity, the energy released by fission reactions is trapped as thermal energy and used to boil water and produce steam. The steam is used to turn a turbine, which powers a generator for the production of electricity.

is alkanes a saturated hydrocarbon?
yup
it's saturated cos it has single bonds
yh....because they don't undergo additional reactions which hydrogen and other atoms can add across the carbon-carbon or triple bond
patience
and me...I'm I wrong?
patience
how does metal looses electron
By oxidation and reduction
hamidat
by oxidation loss
Official
An acid is a proton donor.
what is an acid
an acid is a substance when dissolved in water produces hydrogen ion or hydroxonium ion
hamidat
good
Mudassir
thanks
hamidat
what is ionic bonding
It involves the transferring of electron from a metal to a non mental
hamidat
that's right
Edward
bonding between a metal and a non metal
miriam
calculate the hydrogen ion concentration of the solution when pH=5
no ideas
hamidat
What is thermodynamics
what is the meaning this word twentieth
dhu
Is the branch of physics that deal with heat and temperature and their relation to work, energy and properties of matter
Edward
There are no topics on hydrocarbons
I don't understand
hamidat
its not making sense to me I still don't understand
How and why
Betrice
yes
megan
we need diagram for easy going and understand
serah
How can we easily differentiate between the 5 gas laws
how many carbon is present in alkene
it's the carbon to carbon being double bonded to each other that makes it an alkene, not the amount of carbon itself. ex: C=C, C=C=C. both are alkenes.
Phill
I need more light on alkene
chidera
other usefullness of hydrogen apart from this, it is colourless, odourless and tasteless
it is neutral to litmus paper, it is insoluble in water
hamidat
the enthalpy of a system
changing in heat of a system which can be lost or gained
Yussuf
what is the unit of pressure
what is pressure measured in?
Tim
Pascal
Stupid
millimeter mercury ,mmHg or ATM
hamidat
write the formula of the nitrogen oxide in which nitrogen has oxidation number of 1
N2O
Stupid