Лужноземельні метали

Alkaline Earth Metals of the Periodic Table

The alkaline earth metals are found in group 2A, the second column, of the periodic table. The elements that make up this category are: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

Properties of these elements include:

• Appearance - shiny, silver, softer metals.

• Reactivity - very reactive, but less reactive than alkali metals. Their valence electron shell is a filled s-orbital. So, they typically have a 2+ charge and oxidation state.

• Found in - In nature, they are almost always found combined with other atoms. Most commonly, they form various minerals. For example, calcium is found as calcite or lime. Berylium is found bonded with aluminum and silicon, as beryl. Radium is the most interesting! It only forms from Uranium's radioactive decay chain.

Reactivity of Alkaline Earth Metals

These elements readily undergo chemical reactions. They have very low electronegativities. So, they lose two electrons in chemical reactions. They are very similar to their neighbors, alkali metals. The difference is they are harder and have higher melting and boiling points than alkali metals. They are also less reactive to oxygen and water.

Reactions with halogens create halides.

Halide formation: $$Ca(s)\ +\ Cl_2(g)\ \rightarrow\ CaCl_2(s)$$

Reactions with oxygen form oxides.

Oxide formation: $$Ca(s)\ +\ O_2(g)\ \rightarrow\ CaO(s)$$

Reactions with water form hydroxides, this behavior is why the group is called alkaline because basic (alkaline) compounds are formed.

Hydroxide formation: $$Ca(s)\ +\ HO_2(l)\ \rightarrow\ Ca^{2+}(aq)\ +\ 2\ OH^-(aq)\ + H_2(g)$$

(Video) Group 2 - Alkaline Earth Metals | Properties of Matter | Chemistry | FuseSchool

by FuseSchool - Global Education

This video goes over the properties of the alkaline earth metals. These metals (beryllium, magnesium, calcium, strontium, barium, and radium) make up group $2$ of the periodic table. Much like the alkali metals, these metals become softer and more reactive as you move down the group.