8.3.1 Hydrogen, Alkali Metals, and Alkaline Earth Metals

Question 1

Hydrogen, Alkali Metals, and Alkaline Earth Metals

Answer 1

• The periodic table was constructed by placing elements in order by molecular weight and arranging them in columns by chemical reactivity.
• The periodic table can be broken down into metals, nonmetals, and metalloids.
• Elements within the same group have similar reactivity.

Question 2

note

Answer 2

• Elements were placed in order by molecular weight.
• Elements with similar chemical reactivity were arranged in families (or groups) by columns.
• By putting elements with similar chemical reactivity into groups, it was possible to hypothesize where there may have been “missing” elements which had not yet been discovered.
• Metals are to the left and the bottom of the periodic table.
• Nonmetals are located in the top right corner.
• Metalloids are in between metals and nonmetals.
• Hydrogen can react to gain or to lose an electron.
• Alkali metals tend to form monovalent cations. Alkali metals have the tendency to lose their valence electron. When alkali metals react with water they tend to form the metal cation and OH – , resulting in a basic solution.
• Alkaline earth metals tend to form divalent cations. Alkaline earth metals react with water in a 1:1 ratio to give OH – . When the alkaline earths react with water the resulting solution is basic (or alkaline).

Question 3

In the following chemical reaction, what is oxidized?

2Li + 2H2O → H2(g) + 2Li+ (aq) + 2OH − (aq)

Answer 3

Li

Question 4

Which of the following chemical elements has properties that are most similar to selenium?

Answer 4

Sulfur

Question 5

Which of the following describes the ionization energy trend through the periodic table?

Answer 5

Ionization energy increases from left to right and decreases from top to bottom within a column.

Question 6

In a compound, what is the oxidation number of magnesium?

Answer 6

2+

Question 7

What is the name of the group of elements that react with oxygen in a 1:1 ratio and have a 2+ oxidation state?

Answer 7

Alkaline earth metals

Question 8

Which of the following pairs of elements will react in a similar manner?

Answer 8

Na and K

Question 9

Which of the following groups in the periodic table is made up entirely of metals?

Answer 9

Group 2

Question 10

Which of the following properties is shared by the alkali metals and the alkaline earth metals

Answer 10

They are not found in their elemental state in nature.

Question 11

Which of the following pairs of metals and nonmetals would combine in a 1:1 ratio in a chemical reaction?

Answer 11

Rubidium and Iodine

Question 12

Which of the following elements has the property of being the most nonmetallic?

Answer 12

B