Alkaline Earth Metals
Group 2 metals are reactive but less so than group 1.
About this topic
The alkaline earth metals (group 2: Be, Mg, Ca, Sr, Ba, Ra) have two valence electrons and form +2 ions. They are harder, denser and have higher melting points than group 1 metals, and are less reactive, though reactivity increases down the group.
Their oxides and hydroxides are basic. Magnesium burns in air with a brilliant white flame to form magnesium oxide: 2Mg + O2 gives 2MgO. Calcium reacts slowly with cold water to give calcium hydroxide and hydrogen, while beryllium barely reacts at all. Two electrons must be lost, which takes more energy than one, explaining why they are less reactive than the alkali metals in the same period. Flame tests give calcium brick red, strontium crimson and barium green.
Calcium builds bones and teeth and is the main element of limestone, chalk and cement. Magnesium alloys make lightweight bicycles and aircraft parts, and magnesium sits at the centre of chlorophyll. Milk of magnesia treats indigestion and barium sulfate is swallowed for X-ray images of the gut.
A common error is to write the ion as Mg+ rather than Mg2+. Also, do not confuse group 2 with transition metals; they have no variable charges. Remember that soluble barium compounds are poisonous.
Key ideas
- Two valence electrons
- Form 2+ ions
- Calcium and magnesium are essential
Quick check
Use cases: where Alkaline Earth Metals helps
- Homework: review the key idea behind Alkaline Earth Metals before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Alkaline Earth Metals without notes.
- Visual learning: play with the interactive lab to see how Alkaline Earth Metals changes when you adjust its inputs.
- Teaching a friend: explain Alkaline Earth Metals in your own words, then compare your version with the key ideas.
Chemistry explains medicine, food, cleaning products, fuels and building materials.
Frequently asked questions
What is Alkaline Earth Metals?
Group 2 metals are reactive but less so than group 1.
What will I learn in Alkaline Earth Metals?
Two valence electrons. Form 2+ ions. Calcium and magnesium are essential.
Is Alkaline Earth Metals part of Chemistry?
Yes. It is one of 150 Chemistry topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Alkaline Earth Metals lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Alkaline Earth Metals?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
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