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、天然氣及煤之類的化石燃料是世界上的主要能源。這些天然化石燃料正在快速枯竭，但全世界對化石燃料的需求量卻很大并日益增加。當礦物燃料出現短缺而需求量卻在增長之時，電力生產成本就會增加，電力成本的增加將使商品價格上漲。

    可再生能源是將來能源的重要來源。電能由水電站產生。太陽能正在應用于偏遠地區。油棕櫚加工廠也在利用生物質發電。由風或海浪產生的可再生能源還沒有在我國使用。

    核能將會成為未來替代能源之一。核能是由不穩定核子發生變化而產生的熱能。當一個重核子分裂成兩個結合在一起形成一個更重核子的輕核子時，釋放巨大的能量（核聚變）.

    核裂變是一個不穩定重核受一個中子的轟擊，分裂成兩個（或多個）較輕的核子并釋放出中子及能量的過程。這兩個核子叫作裂變產物。

    核裂變之后的總質量稍低于裂變前的質量，虧損的質量轉化成巨大的核能，并釋放出中子。

    核裂變只能在某種類型的重核及不穩定核素內發生，如鈾-235及钚-239.

    當一個慢中子轟擊一個鈾-235核子時，鈾-235核子分裂成兩個較輕的核子：鋇-141和氪-92,并產生兩個或三個中子，同時釋放出核能。

    產生的中子將轟擊更多的鈾-235核子，會產生更多的中子并釋放更大的核能。轟擊過程不斷進行，中子的釋放也不斷進行，形成鏈式反應。

    非受控鏈式反應發生在原子彈爆炸之時，二戰期間，廣島和長崎的原子彈爆炸釋放出巨大的能量及放射性輻射，引起慘重的生命及財產損失。

    核反應堆內，鏈式反應的量受到控制，從而決定產生的核能的量。核反應堆內的硼棒吸收中子，這會使轟擊鈾-235的中子的數量受到控制。

    石墨堆芯降低中子速度。慢中子較快中子更可能使鈾-235發生裂變。

    核聚變是兩個較輕的核子形成一個較重且更穩定的核子并釋放出巨大核能的過程。鈾-235含量較高的濃縮鈾燃料用于核能的生產。

    太陽的光能和熱能是由于氫原子在極高的溫度和壓力下發生核聚變的緣故。

    核聚變中，氫-2（氘）和氫-3（氚）在極高的壓力和溫度下結合成為一個較重的氦核。產生一個中子及巨大的核能。

    然而，核聚變中的原子量虧損比核裂變中的稍多一些。因此，核聚變產生的能量比核裂變產生的能量大。

    氫-2和氫-3同位素一般用于核聚變。

    核聚變用來制造氫彈。氫彈比原子彈釋放的能量更大。