Use reference table S. Of the choices given, (2), Mg (atomic number 12) has the largest atomic radius.

The energy need to remove the most loosely held electron from a gaseous atom in the ground state is known as the first ionization energy. Use reference table S. Of the choices given, sodium, (atomic number 12) has the largest atomic radius.

A solid element that is brittle and a poor conductor of electricity is most likely a non-metal. Refer to the Periodic Table only S (sulfur) is a non-metallic element.

Diamond and graphite has different molecular structures. Therefore they have different chemical and physical properties.

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Metalloids are B, Si, Ge, As, Sb, Te, Po, and At.

Al is the ONLY element that touches the line in your Reference Table that is a metal, all others are metalloids.

Metals can be found below the line – Al, Ga, In, Ti, Sn, Pb, Bi, etc (to the left of the line).
Non-metals can be found above the line or to the right – C, N, P, O, S, Se, Br, I, etc.

Use the Periodic Table of Elements. Chlorine (Cl atomic number 17) has an oxidation number of -1. In the compound MCl, the oxidation state of M must be +1.

Use the Periodic Table of the Elements and Reference Table S. As one proceeds across Period 3 from Na to Ar, the properties of elements change from metal to metalloid to nonmetal to noble gas. Therefore, the metallic properties decrease. Table S reveals that the atomic radii of the eight successive elements all decrease from 190 pm to 88 pm.

Use the Periodic Table of Elements. When atom bond, they generally complete a valence shell that will contain either 2 or electrons. Since an atom of argon (Ar, atomic number 18) is a noble gas and already has 8 valance electrons, it will not bond with another atom.