The Elements of the Periodic Table...to be continued

How many elements are in the periodic table of elements?

118!

Which three groups of the Periodic Table contain the most elements classified as metalloids (semimetals)? 1, 2, and 13 2, 13, and 14 14, 15, and 16 16, 17, and 18

14, 15, and 16 : Go to the Periodic Table and note the location of the stepped line dividing metals and nonmetals. Elements next to the left or right of this line are metalloids. Choice three includes 5 metalloids.

Which compound forms a colored aqueous solution? CaCl22 CrCl3 NaOH KBr

CrCl3 Colored aqueous solutions are a characteristic of transition compounds. The only transition compound in the above choices is CrCl3. Cr is a transition element.

Which element has the highest first ionization energy? sodium aluminum calcium phosphorus

Phosphorus Phosphorus (P) has a first ionization energy of 1012 kJ/mol.