Write the formulas for the higher oxides of elements with atomic numbers 4, 12, 20 and arrange them in the order

Write the formulas for the higher oxides of elements with atomic numbers 4, 12, 20 and arrange them in the order of strengthening of the basic properties. For the element that forms the most basic oxide, draw up the electronic formula of the atom, depict the arrangement of the valence electrons in the orbitals of the atom in the ground and excited states, and determine the possible valences of the atom. Draw up the electronic and graphic formulas of the higher hydroxide of this element and indicate the type of chemical bond between the atoms.

Chemical elements with No. 4 – Be; No. 12 – Mg; No. 20 – Ca.
Metal oxides have the formulas: BeO, MgO, CaO
Electronic formula of calcium atom: 1S2 | 2S2 2P6 | 3S2 3P6 | 4S2
Orbital distribution of electrons of the Ca atom: +20 Ca) 2) 8) 8) 2
The Ca atom has no excited state, although there are vacant 3P and 3d orbitals.
The outer electronic level of a calcium atom contains two valence electrons. The oxidation state is Ca +2. Ground state energy diagram: 4S2. The valence value in the compounds is 2. The hydroxide formula is Ca (OH) 2.
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Graphic Formula: Ca
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The chemical bond in the Ca (OH) 2 molecule is ionic.