Which families of metals are not so reactive, which allows them to exist by themselves in nature?
The families of metals that are not so reactive and can exist by themselves in nature are:
1. Noble Gases (Group 18): This includes helium, neon, argon, krypton, xenon, and radon. Noble gases have a full outer electron shell, making them very stable and unreactive. They rarely form compounds with other elements.
2. Alkali Metals (Group 1): This includes lithium, sodium, potassium, rubidium, cesium, and francium. Alkali metals are highly reactive and do not exist freely in nature. They readily react with water and oxygen, making them unstable in their pure form.
3. Alkaline Earth Metals (Group 2): This includes beryllium, magnesium, calcium, strontium, barium, and radium. Alkaline earth metals are less reactive than alkali metals but still tend to form compounds with other elements. They are commonly found as minerals in the Earth's crust.
4. Transition Metals (Group 3-12): Transition metals, such as iron, copper, silver, and gold, have moderate reactivity. While they can react with certain elements and compounds, many transition metals are relatively stable and can be found in their pure form in nature, especially precious metals like gold and silver.
5. Lanthanides and Actinides (Inner Transition Metals): These are the elements located at the bottom of the periodic table, including elements such as lanthanum, uranium, and plutonium. Lanthanides and actinides are generally highly reactive and tend to form compounds. However, some of these elements can exist in their pure form in nature, particularly rare earth metals like cerium and neodymium.
It's important to note that even though some metals are less reactive and found in nature in their pure form, they may undergo oxidation or corrosion when exposed to air, water, or other reactive substances over time.