3.1.2 - Group 2 Flashcards
What are the elements in Group 2 of the periodic table called?
The elements in Group 2 of the periodic table are called the alkaline earth metals.
What are the elements in Group 2?
The elements in Group 2 are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
What is the trend in atomic radius as you move down Group 2?
As you move down Group 2, the atomic radius increases because additional electron shells are added, making the atoms larger.
How does ionization energy change as you move down Group 2?
Ionization energy decreases as you move down Group 2 because the outer electrons are further from the nucleus and experience more shielding, making them easier to remove.
What is the general trend in melting point across Group 2?
Melting points generally decrease as you move down Group 2, with the exception of magnesium, which has a higher melting point than expected due to its crystal structure.
How does reactivity change as you go down Group 2?
Reactivity increases as you go down Group 2 because the ionization energy decreases, making it easier for the elements to lose electrons and react with other substances.
What happens when Group 2 metals react with water?
Group 2 metals react with water to produce a metal hydroxide and hydrogen gas. The reactivity increases down the group, with magnesium reacting slowly and barium reacting most vigorously.
What is the general reaction when a Group 2 metal reacts with water?
The reaction is:
Metal+2H2O→Metalhydroxide+Hydrogengas
How does calcium react with water compared to magnesium?
Calcium reacts more vigorously with water than magnesium. Magnesium reacts slowly, especially at room temperature, while calcium reacts more rapidly and produces heat.
What is the trend in the solubility of hydroxides as you move down Group 2?
The solubility of hydroxides increases down Group 2, with barium hydroxide (Ba(OH)₂) being the most soluble.
How does Group 2 metal oxide react with water?
Group 2 metal oxides react with water to form alkaline hydroxides. For example,
CaO+H2O→Ca(OH)2
What is the reaction of magnesium oxide (MgO) with water?
Magnesium oxide (MgO) reacts with water to form magnesium hydroxide (Mg(OH)₂), which is only slightly soluble in water and forms a weakly alkaline solution.
What happens when Group 2 metals react with oxygen?
Group 2 metals react with oxygen to form metal oxides. For example:
2Ca + O2 → 2CaO
How does the basicity of oxides change down Group 2?
The basicity of oxides increases as you move down Group 2 because the oxides become more soluble in water and produce stronger alkaline solutions.
What is the trend in thermal stability of Group 2 carbonates?
The thermal stability of Group 2 carbonates increases as you move down the group. This means that the carbonates of heavier elements like barium carbonate (BaCO₃) decompose at higher temperatures than those of lighter elements like magnesium carbonate (MgCO₃).
How does barium carbonate (BaCO₃) decompose upon heating?
Barium carbonate (BaCO₃) decomposes to form barium oxide (BaO) and carbon dioxide (CO₂) when heated:
BaCO3→BaO+CO2
What is the trend in alkalinity of hydroxides as you move down Group 2?
The alkalinity of hydroxides increases as you move down Group 2. For example, calcium hydroxide (Ca(OH)₂) is more alkaline than magnesium hydroxide (Mg(OH)₂), and barium hydroxide (Ba(OH)₂) is the most alkaline.
What happens when Group 2 hydroxides dissolve in water?
When Group 2 hydroxides dissolve in water, they form alkaline solutions. The solubility increases as you move down the group, so barium hydroxide is the most soluble and gives the strongest alkaline solution.
What is the trend in the formation of sulfate salts in Group 2?
Sulfate salts of Group 2 metals are generally insoluble in water, but the solubility increases as you move down the group. For example, barium sulfate (BaSO₄) is more soluble than magnesium sulfate (MgSO₄).
How do Group 2 elements react with acids?
Group 2 elements react with acids to form salts and hydrogen gas. For example,
Ca+2HCl→CaCl2+H2
What is the trend in solubility of sulfates as you go down Group 2?
The solubility of Group 2 sulfates decreases down the group. Magnesium sulfate (MgSO₄) is very soluble, while barium sulfate (BaSO₄) is almost insoluble in water.
What is magnesium hydroxide commonly used for?
Magnesium hydroxide (Mg(OH)₂) is commonly used as an antacid to neutralize stomach acid.
How is barium sulfate (BaSO₄) used in medicine?
Barium sulfate (BaSO₄) is used as a radiopaque contrast medium in X-ray imaging to outline the gastrointestinal tract.
What is the trend in ionization energy in Group 2 elements?
The first ionization energy decreases as you go down Group 2 because the outer electrons are further from the nucleus and are shielded by more inner electrons.
Why does barium react most vigorously with water?
Barium reacts most vigorously with water because it has the lowest ionization energy in Group 2, making it the easiest to lose electrons and form hydroxide ions.
