Chemistry Level 10 - Alkali & Alkaline Earth Metals

A chemical reaction where a substance gains oxygen.

A chemical reaction where a substance loses oxygen.

A chemical reaction where oxidation and reduction happen simultaneously.

A measure of a substance's ability to lose electrons and form positive ions.

A vertical column in the periodic table.

A horizontal row in the periodic table.

An element in group 2 of the periodic table.

A measure of the hydrogen ion concentration in a solution.

The tendency of elements in a group (vertical column) to become more reactive as you move down the group.

As you move down the group, atomic size increases due to the addition of electron shells. This leads to weaker attraction between the valence electron and the nucleus, making it easier to lose the electron and react.

Electrons in inner shells shield the valence electron from the positive charge of the nucleus. As you move down the group, more inner shells exist, increasing shielding and decreasing the attraction between the nucleus and valence electron.

The color of the flame produced when an alkali metal is heated in a flame.

Alkali metals are used in various ways, including making batteries (lithium-ion batteries), producing light (sodium vapor lamps), and creating alloys (sodium-potassium alloy).

Alkali metals are highly reactive, especially with water. This reactivity poses a significant safety risk. Hence, they are stored under oil to prevent contact with air and moisture.

Protecting oneself from the dangers of alkali metals when handling them in laboratories and industrial settings.

Alkali metals are stored under oil to prevent their reaction with oxygen and moisture. This prevents fires and explosions.

Hard water contains beneficial minerals like calcium and magnesium, which contribute to bone health, cardiovascular health, and overall well-being.

The presence of minerals in hard water can enhance the taste of drinking water, which some people prefer.

The minerals in hard water create a protective layer on pipes, reducing the leaching of toxic metals like lead.

Hard water can form limescale deposits in pipes, boilers, and appliances, reducing efficiency and potentially causing costly repairs.

Hard water reacts with soap to produce a white, insoluble substance called soap scum, reducing the effectiveness of soap and leaving residue.

Hard water can make laundry feel stiff and rough because it prevents detergents from fully dissolving and interacting with fabrics. It can also cause colours to fade more quickly.

The chemical reaction between hard water and a sodium-based ion-exchange resin removes calcium and magnesium ions, softening the water.

Washing soda removes calcium ions by reacting with them to form calcium carbonate precipitate, which is then removed.

Alkali metals are highly reactive, so specific precautions must be taken in the lab to prevent accidents. Work with them in a fume hood, wear safety goggles and gloves, and avoid contact with water because they react violently.

Lithium burns with a crimson red flame, sodium produces a bright yellow flame, and potassium exhibits a lilac-colored flame.

Electron shielding refers to the effect of inner electrons blocking the outer electrons from the full attraction of the nucleus. This shielding effect weakens the electrostatic attraction and makes alkali metals highly reactive.

Alkali metals readily react with halogens (e.g., chlorine, bromine) to form ionic compounds called halides. These compounds are typically white, crystalline solids.

Alkali metals are highly reactive towards oxygen and moisture in air. Storing them under oil prevents their reaction with air and water, thereby preserving their properties.

Francium is the least stable alkali metal because its nucleus has a high number of protons and neutrons, making it susceptible to radioactive decay. It has the shortest half-life among alkali metals.

When sodium reacts with water, it produces a hissing sound, heat, and a solution that turns the indicator phenolphthalein pink. This is a vigorous reaction demonstrating the high reactivity of sodium.

Cesium is the most dangerous Group 1 metal due to its extreme reactivity. It reacts explosively with water, generating a large amount of heat and potentially causing fires.

A chemical reaction where concentrated hydrochloric acid (HCl) reacts with manganese (IV) oxide (MnO₂) to produce chlorine gas, manganese chloride, water, and heat.

Chlorine gas turns moist blue litmus paper red and then bleaches it white. This happens because Chlorine is acidic and a strong bleach.

Hydrogen chloride gas (HCl) dissolves in water to form hydrochloric acid.

Hydrogen chloride gas (HCl) dissolves in methylbenzene but doesn't ionize. It doesn't behave as an acid.

A chemical reaction where a more reactive element displaces a less reactive element from its compound.

Metals that are very hard, strong, and good conductors of heat and electricity. They have high melting points and densities.

Forming colored compounds, with more than one oxidation state/valence, and acting as catalysts.

The number of electrons an atom loses or gains when forming a chemical bond.

They can lose different numbers of electrons depending on what they are reacting with.

Iron can form Fe2+ by losing 2 electrons or Fe3+ by losing 3 electrons.

Copper can form Cu+ by losing one electron or Cu2+ by losing two electrons.

Transition metal compounds with +2 valence are named with Roman numerals.

Iron reacting with steam, hydrochloric acid, and chlorine gas.