Which elements in the periodic table are lethal

These elements are so dangerous that they are sometimes labeled “the world’s most lethal elements.” But on what basis are they given this label?

They are distinguished based on three main categories: radioactivity, toxicity, and reactivity.
 

First, let’s talk about radioactivity. What exactly do we mean by an element’s radioactivity?

In 1896, French physicist Henri Becquerel discovered radioactivity. At that time it was seen simply as a natural phenomenon: the nuclei of some unstable elements in the periodic table break down spontaneously and emit various types of radiation or particles. This phenomenon is called radioactivity. Examples include elements such as uranium, radium, and polonium. These are radioactive elements. Their nuclei emit alpha, beta, or gamma radiation. These radiations have high penetrating power and are extremely harmful to living tissue.
 

Two points are worth mentioning here. First, Marie and Pierre Curie made significant contributions to the study of radioactivity around the same time; for their work, Becquerel and the Curies were jointly awarded the 1903 Nobel Prize in Physics. Second, later Lise Meitner and Otto Hahn explained nuclear fission. In this way, artificial radioactivity and methods to induce fission in elements like uranium were discovered.
 

Next, let’s move to the toxicity of elements. What is meant by an element’s toxicity?
Toxicity is a general measure of how harmful an element is to health or the environment. For example, when a venomous snake bites you, the affected area typically swells and blood may clot. Similarly, if we inhale or ingest certain toxic elements, they cause poisoning in our bodies. If toxic elements contaminate the environment, they can poison other living organisms as well.
 

Then there is an element’s tendency to react. A useful measure of how quickly an element reacts with other elements to form new compounds is its reactivity. Generally, the easier it is for an element to lose electrons from its outermost shell (metals) or the more readily an element accepts electrons from other atoms (nonmetals), the higher its reactivity. But why is high reactivity dangerous?
 

Some elements in the periodic table are so reactive that they catch fire upon slight contact with air or explode violently on contact with water. Interestingly, some elements that are highly toxic or highly reactive can form compounds that are completely safe  compounds we use every day. For example, sodium is an extremely reactive element, and chlorine is a toxic element. Yet the compound they form, sodium chloride, is common table salt that we eat and use in cooking daily.
 

Now let’s briefly learn about some of the hazardous elements in the periodic table.

1. Hydrogen
   This is the first element in the periodic table. It is highly flammable  it catches fire very easily. When mixed with air, it can ignite or explode. But hydrogen also reacts with oxygen to form water, an essential substance for life.
    

2. Cesium
   This is element number 55 in the periodic table. It is flammable and explosive. Exposed to air it can catch fire, and it explodes violently on contact with water.
    

3. Chromium
   This is element number 24 in the periodic table. It appears silvery-gray and shiny, so chromium metal is sometimes used in various car parts. However, the hexavalent state of chromium (Cr‑VI), where the atom shares six electrons, can cause cancer. That form is called carcinogenic chromium  carcinogenic meaning cancer-causing.
    

4. Cadmium
   Element number 48 in the periodic table. It is toxic and appears silvery-white. Chemically it resembles zinc. Presence of cadmium in the human body interferes with calcium function.
    

5. Thallium
   This is element number 81 in the periodic table. Thallium is well known for its toxicity. Even small amounts are highly poisonous. Its presence in the human body disrupts cellular physiological functions.
    

6. Lead
   English name: lead. Extremely toxic. It is element number 82 in the periodic table. Lead was once widely used in printing presses, paints, and petrol, but because of its severe toxicity its use has been restricted. When lead enters the human body it can cause extensive damage to the brain and kidneys.
    

7. Arsenic
   Arsenic occupies position 33 in the periodic table. Its toxicity is notorious. It sits directly below phosphorus in the periodic table  they belong to the same group  so it shares many properties with phosphorus. Phosphorus is an essential element for the body, but our cells sometimes mistake arsenic for phosphorus, causing severe disruption of cellular functions.
    

8. Fluorine
   Fluorine is the ninth element in the periodic table. Its atomic structure makes it extremely eager to accept electrons from other atoms (it has the highest electronegativity). Therefore fluorine is highly reactive. It also has great corrosive power and can corrode almost anything. Fluorine has a notorious reputation as a corrosive element.
    

9. Antimony
   Antimony is located directly below arsenic in the periodic table, with atomic number 51. The toxic effects of the two elements are quite similar. Antimony damages the human liver, and poisoning causes severe vomiting.
    

10. Plutonium
    Radioactive plutonium’s atomic properties are used in the making of nuclear weapons. Its atomic number is 94. Plutonium is highly radioactive. Being radioactive means its atoms decay, emitting alpha, beta, and gamma radiation, which can cause severe damage to living cells. The “Fat Man” bomb dropped on Nagasaki was the second atomic bomb used in war and was made with radioactive plutonium-239 (Pu‑239).