Alkaline earth metals, which belong to Group 2 of the periodic table, have several similarities, primarily related to their chemical properties. Here are the key similarities:
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Chemical Properties:
- Alkaline earth metals have similar chemical properties due to their similar electron configuration. They all have two electrons in their outermost shell (valence shell). This makes them highly reactive, though less so than alkali metals in Group 1. They readily lose these two valence electrons to form cations with a +2 charge.
- They typically react with water (though less vigorously compared to alkali metals) and form hydroxides, and they also react with halogens to form ionic compounds.
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Total Electrons:
- All alkaline earth metals have a total of 2 electrons in their outer shell. The total number of electrons in neutral atoms equals the number of protons. Therefore, each alkaline earth metal will have a total number of electrons equal to its atomic number (which varies from 4 for beryllium to 88 for radium).
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Protons and Neutrons:
- The number of protons is equal to their atomic number, which also varies across the group. However, the number of neutrons varies as well, depending on the specific isotope of each element. Generally, the number of neutrons can be deduced by subtracting the atomic number from the atomic mass (rounded to the nearest whole number).
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Periods:
- All alkaline earth metals are found in Periods 2 through 7 of the periodic table. Beryllium (Be) is in Period 2, magnesium (Mg) in Period 3, calcium (Ca) in Period 4, strontium (Sr) in Period 5, barium (Ba) in Period 6, and radium (Ra) in Period 7.
In summary, the most similar characteristic of alkaline earth metals relates to their chemical properties, specifically their common reactivity patterns and oxidation states associated with their valence electron configurations.