The biggest disclosure of metal! How much do you know?（3）
Alkaline earth metals are the most active elements
Barium: Barium has great chemical activity and is the most active among alkaline earth metals. It was not until 1808 that it was classified as a metallic element.
The coldest metal
Tin: When the temperature is below -13.2 ℃, tin begins to crumble; When the temperature is below -30~-40 ℃, it will immediately turn into powder, a phenomenon commonly known as "tin epidemic".
The metal with the highest toxicity to humans
Plutonium: Its causative effect is 486 million times that of arsenic, and it is also the strongest carcinogen. 1 × 10-6 grams of plutonium can cause cancer in humans.
The largest natural gold
It was discovered by Hope Star Gold Company on October 19, 1872 in the Hilonde area of Australia, weighing 214.3 kilograms.
The largest natural silver
Found in the Sonora region of Mexico, weighing 1026.5 kilograms.
The largest natural copper
Weighing 26 tons, it was discovered in 1977 at the Horton Quincy Mine in Michigan, USA.
The largest reserve of radioactive elements in seawater
Uranium: Uranium is the largest radioactive element in seawater, estimated to be 4 billion tons, which is 1544 times the amount of uranium stored on land.
The element with the highest content in seawater
Potassium: Potassium exists in the form of potassium ions in seawater, with a content of about 0.38g/kg, and is the highest element in seawater.
The metal with the highest atomic number among stable elements
Lead: Lead has the highest atomic number among all stable chemical elements. There are four stable isotopes in nature: lead 204, 206, 207, and 208.
The most common human allergenic metals
Nickel: Nickel is the most common allergenic metal, and about 20% of people are allergic to nickel ions.
