Metals because metals are mostly on the left side of the Periodic Table and have fewer electrons.
The number of covalent bonds an element can form depends on the number of valence electrons it has. In general, elements can form a number of covalent bonds equal to the number of valence electrons needed to reach a full valence shell (usually 8 electrons). For example, element X can form up to 4 covalent bonds if it has 4 valence electrons.
Silicon is an element in group 14. It has four valence electrons. Silicon tends to share electrons rather than releasing or obtaining four electrons (which needs tremendous energy). Hence it forms covalent bonds.
Tin can form up to 4 bonds, since it has 4 valence electrons available for bonding.
Oxygen has 6 covalent electrons, since it has 6 valence electrons and tends to form two covalent bonds.
Ionic bonds form when one element transfers electrons to another element. This occurs when an element with a high electron affinity (EA) transfers electrons to an element with a low ionization energy (IE). The transfer of electrons creates ions that are held together by electrostatic forces, forming an ionic bond.
Non-metals
The number of covalent bonds an element can form depends on the number of valence electrons it has. In general, elements can form a number of covalent bonds equal to the number of valence electrons needed to reach a full valence shell (usually 8 electrons). For example, element X can form up to 4 covalent bonds if it has 4 valence electrons.
Silicon is an element in group 14. It has four valence electrons. Silicon tends to share electrons rather than releasing or obtaining four electrons (which needs tremendous energy). Hence it forms covalent bonds.
Tin can form up to 4 bonds, since it has 4 valence electrons available for bonding.
Oxygen has 6 covalent electrons, since it has 6 valence electrons and tends to form two covalent bonds.
nitrogen, it tends to form high energy bonds that are easily broken.
Ionic bonds form when one element transfers electrons to another element. This occurs when an element with a high electron affinity (EA) transfers electrons to an element with a low ionization energy (IE). The transfer of electrons creates ions that are held together by electrostatic forces, forming an ionic bond.
If an element has less than four valence electrons, it will tend to lose its valence electrons and form cations. If an element has more than four valence electrons, it will tend to gain electrons and form anions. An element that has four valence electrons will tend to form covalent bonds rather than ionic bonds.
silicon prefers to share electrons forming covalent bonds
Sulphur has six valence electrons and hence it can form maximum of six covalent bonds as in SF6.
Polonium is a metalloid element and it can form both ionic and covalent bonds. In general, polonium tends to form covalent bonds with nonmetals, and can also form ionic bonds with highly electronegative elements.
The valence electrons of an atom determine how the element forms chemical bonds with other elements to form chemical compounds.