SPM Form 4 Chemistry Notes — Chapter 2『2.3』Isotopes and Their Importance

2.3 Isotopes and their Importance

● Isotopes are atoms of the same element with the same number of proton but different number of neutrons / same proton number but different nucleon number.『同样element的isotopes拥有一样数量的proton，不一样数量的neutrons / 一样proton数，不一样Necleon数』

● Example of element with isotopes ：Hydrogen（Hydrogen-1，Hydrogen-2，Hydrogen-3）；Carbon（Carbon-12，Carbon-13，Carbon-14）；Oxygen（Oxygen-16，Oxygen-17，Oxygen-18）

● Isotopes of the same element have the same chemical properties because they have the same number of electrons.『Isotopes有一样的Chemical properties，因为它们的electron的数量是一样的』

● Isotopes of the same element have different physical properties （eg：density，boiling point）because they have different number of neutron.（different mass/size）『Isotopes有不一样的Physical properties，因为它们有不一样的neutron数量』

Uses of isotopes in daily life

● Isotopes can be divided into radioactive and non-radioactive isotopes.Radioisotopes can give off radiation in the form of gamma，beta or alpha ray.『Isotopes 有分为放射性isotopes和无放射性isotopes。放射性isotopes会发射出辐射』

Uses of isotopes in archeological uses

Carbon-14	To estimate the age of bone，wood or fossil.『估计骨头，木材，化石的岁数』
Carbon-14	Helped in understanding the photosynthesis and protein synthesis.

Uses of isotopes in medical uses

Iodine-131	To treat thyroid diseases.『治疗甲状腺疾病』
Gamma-ray from cobalt-60	•Treatment of cancer.『治疗癌症』 •Destroy bacteria in food.『破坏食物中的细菌』
Phosphorus-32 or strontium-90	To treat superficial cancer such as skin cancer.『治疗表面癌症如皮肤癌』

Uses of isotopes in other fields

Sodium-24	To detect leakage of underground pipes.『探测地下管道的泄漏』
Uranium-235	Fuel used in nuclear power stations.『核电站使用的燃料』
Krypton-85	Control the thickness of plastic.『控制塑料的厚度』