What are alkaline earth metals, and how do they differ from alkali metals? Provide the electronic configuration of Ca, Ba, and Be.

Here are the answers to your questions:

1. Explain the term 'alkaline earth metals'. Alkaline earth metals are the elements found in Group 2 of the periodic table. They are reactive metals that readily lose their two valence electrons to form ions with a +2 charge. They are typically silvery-white, somewhat reactive at standard temperature and pressure, and have relatively low densities and melting points.

2. What is the difference between alkaline metals and alkaline earth metals? The main difference lies in their electron configuration and reactivity. Alkali metals (Group 1) have one valence electron, forming +1 ions and are extremely reactive. Alkaline earth metals (Group 2) have two valence electrons, forming +2 ions, and are reactive but generally less so than alkali metals. Alkali metals are also softer and have lower melting points than alkaline earth metals.

3. Write the electronic configuration of Ca, Ba and Be using spdf form.

   • Beryllium (Be) (Atomic number 4): $$\boxed{1s^2 2s^2}$$
   • Calcium (Ca) (Atomic number 20): $$\boxed{1s^2 2s^2 2p^6 3s^2 3p^6 4s^2}$$
   • Barium (Ba) (Atomic number 56): $$\boxed{1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10} 5p^6 6s^2}$$