Calcium reacts with cold water more rapidly than magnesium because more energy is needed to remove the outer electrons in magnesium. This is true even though calcium atoms have a greater nuclear charge. Explain why more energy is required to remove the outer electrons in magnesium than in calcium.
$0.001\,\text{mol}$ of strontium is reacted with an excess of cold water. Once the reaction is complete, a colourless solution is seen. Construct the equation for the reaction of strontium with cold water. Include state symbols.
$0.005\,\text{mol}$ of calcium and $0.005\,\text{mol}$ of strontium are added separately to two beakers. Each beaker contains $100\,\text{cm}^3$ of cold water. At the end of both reactions, a white solid and a colourless solution are observed in both beakers. Predict which element, calcium or strontium, produces the more alkaline solution. Explain your answer.
Describe one observation that occurs when magnesium carbonate is added to excess dilute sulfuric acid.
Element $X$ is a metal. $X$ reacts with oxygen to make a black solid oxide. In this oxide, the oxidation state of $X$ is $+2$. The carbonate of $X$, $XCO_3$, is a green solid. On heating, it decomposes to the oxide and a colourless gas. Using the information given, state two similarities and one difference between metal $X$ and its compounds and Group 2 metals and their compounds.
Write the formula for the oxide of $X$.
Write an equation for the reaction of $XCO_3$ on heating.