Fossils fuels such as petroleum, natural gas and coal are the major sources of energy in the world. These natural fossil resources are depleting fast but the worldwide consumption of fossils fuels is high and keeps on increasing. When there is a shortage of fossil fuels is high and keeps on increasing. This will increase the production cost of electrical energy. The increase in the cost of electrical will increase the price of goods.

    Renewable energy will be an important source of energy in the future. Electrical energy is generated in hydroelectric power plants. Solar energy is being used in some remote areas. Oil palm refinery plants also use biomass to generate electrical energy. Renewable energy generated from the wind or waves is not used in our country.

    Nuclear energy will be one of the alternative sources of energy in the future. Nuclear energy is the heat energy produced from the changes in an unstable nucleus. A large amount of nuclear energy is produced when a heavy nucleus splits in two light nuclei join to form a heavier nucleus （nuclear fusion）.

    Nuclear fission is a process where an unstable and heavy nucleus is bombarded by a neutron, causing it to split into two （or more） lighter nuclei together with the release of neutrons and energy. The two nuclei are called fission products.

    The total mass after nuclear fission is slightly lower than the mass before fission. The loss in mass is converted into a large amount of nuclear energy and neutrons are released.

    Nuclear fission can only occur in some types of heavy and unstable nuclei such as in the uranium -235 and plutonium -239.

    When a slow-moving neutron bombards a uranium -235 nucleus, the uranium -235 will split into two lighter nuclei, which is the barium -141 nucleus and the krypton -92 nucleus. Two or three neutrons, together with nuclear energy are also produced.

    The neutrons which are produced will bombard more uranium -235 nuclei. This will produce more neutrons and more nuclear energy is released. The process of bombardment will repeat and the release of neutrons is repeated, resulting in a chain reaction.

    An uncontrolled chain reaction happens during the explosion of an atomic bomb. The Hiroshima and Nagasaki atomic bomb explosions during world War II released a large amount of nuclear energy and radioactive radiation which caused a great loss of human lives and property.

    In a nuclear reactor, the number of chain reactions is controlled to determine the amount of nuclear energy that will be produced. The boron rods inside a nuclear reactor absorb neutrons. This will control the number of neutrons that bombard the uranium -235 nuclei.

    The speeds of neutrons are slowed down by the graphite core. The fission of uranium -235 is more likely to occur with slow neutrons than with fast neutrons.

    Nuclear fusion is a process where two light nuclei to form a heavier, more stable nucleus together with the release of a large amount of nuclear energy. Enriched uranium fuel that has a higher proportion of uranium -235 is used in the production of nuclear energy.

    The heat and light energy from the Sun is due to the fusion of hydrogen atoms at a very high temperature and pressure.

    In nuclear fusion, hydrogen -2 （deuterium） and hydrogen -3 （tritium） are combined at a very high temperature and pressure to produce a heavier helium nucleus. A neutron and a large amount of nuclear energy are produced.

    However, the atomic mass loss in nuclear fusion is slightly more than that of nuclear fission. Hence nuclear fusion will produce more nuclear energy than nuclear fission.

    Normally hydrogen -2 and hydrogen -3 isotopes are used in nuclear fusion.

    Nuclear fusion is used to make hydrogen bombs. Hydrogen bombs release more nuclear energy than atomic bombs

    石油、天然气及煤之类的化石燃料是世界上的主要能源。这些天然化石燃料正在快速枯竭，但全世界对化石燃料的需求量却很大并日益增加。当矿物燃料出现短缺而需求量却在增长之时，电力生产成本就会增加，电力成本的增加将使商品价格上涨。

    可再生能源是将来能源的重要来源。电能由水电站产生。太阳能正在应用于偏远地区。油棕榈加工厂也在利用生物质发电。由风或海浪产生的可再生能源还没有在我国使用。

    核能将会成为未来替代能源之一。核能是由不稳定核子发生变化而产生的热能。当一个重核子分裂成两个结合在一起形成一个更重核子的轻核子时，释放巨大的能量（核聚变）.

    核裂变是一个不稳定重核受一个中子的轰击，分裂成两个（或多个）较轻的核子并释放出中子及能量的过程。这两个核子叫作裂变产物。

    核裂变之后的总质量稍低于裂变前的质量，亏损的质量转化成巨大的核能，并释放出中子。

    核裂变只能在某种类型的重核及不稳定核素内发生，如铀-235及钚-239.

    当一个慢中子轰击一个铀-235核子时，铀-235核子分裂成两个较轻的核子：钡-141和氪-92,并产生两个或三个中子，同时释放出核能。

    产生的中子将轰击更多的铀-235核子，会产生更多的中子并释放更大的核能。轰击过程不断进行，中子的释放也不断进行，形成链式反应。

    非受控链式反应发生在原子弹爆炸之时，二战期间，广岛和长崎的原子弹爆炸释放出巨大的能量及放射性辐射，引起惨重的生命及财产损失。

    核反应堆内，链式反应的量受到控制，从而决定产生的核能的量。核反应堆内的硼棒吸收中子，这会使轰击铀-235的中子的数量受到控制。

    石墨堆芯降低中子速度。慢中子较快中子更可能使铀-235发生裂变。

    核聚变是两个较轻的核子形成一个较重且更稳定的核子并释放出巨大核能的过程。铀-235含量较高的浓缩铀燃料用于核能的生产。

    太阳的光能和热能是由于氢原子在极高的温度和压力下发生核聚变的缘故。

    核聚变中，氢-2（氘）和氢-3（氚）在极高的压力和温度下结合成为一个较重的氦核。产生一个中子及巨大的核能。

    然而，核聚变中的原子量亏损比核裂变中的稍多一些。因此，核聚变产生的能量比核裂变产生的能量大。

    氢-2和氢-3同位素一般用于核聚变。

    核聚变用来制造氢弹。氢弹比原子弹释放的能量更大。