Question

Use the periodic table to choose the element that matches each description.

Answer 1

Answer:

The periodic table is arranged in periods and in groups. Periods tell us the energy level of these elements and the groups tell more about the characteristics.

Elements found in the same groups have similar characteristics. Elements in the same group are arranged vertically, or they are found in the same column.  

The halogen group is also known as Group VIIA or Group 17. It is the second to the last column of the periodic table. They are highly reactive and are non-metals. They have 7 valence electrons. The elements that fall in this group are:

• Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At) and Tenessine (Ts).

Group IIA is also known as the Alkaline Earth Metals. They are reactive and form ionic bonds with non-metals. They have 2 valence electrons. This group is found in the 2nd column from the left side of the periodic table. The elements that fall in this group are:

• Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra).

The most non-reactive elements are found in the last column on the right side of the periodic table. This group is called Group VIIIA or Group 18, collectively known as Noble gases. These elements are not reactive because they have a filled outer energy levels, or they have complete 8 valence electrons (except Helium, which has 2 but it completes the shell). The elements that fall under this group are:

• Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn).

Alkali metals are found in the 1st column from the left in the periodic table (except for Hydrogen). This group is also called Group 1 or Group IA. They are reactive and often form salts. The elements that fall under this group are:

• Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), Francium (Fr).

Answer 2

halogen: Iodine

group IIA: Magnesium

nonreactive: Argon

alkali metal: Potassium