Explanation

The electronegativity of aluminum is 1.5.

The electronegativity of beryllium is 1.5. > The electronegativity of aluminum is similar to the electronegativity of beryllium

Explanation

Some materials hold their electrons very tightly. Electrons do not move through them very well. These things are called Insulators.

In some materials such as glass, rubber, wood and most plastics, the electrons are held quite tightly.

These materials are called insulators.
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Explanation

• Litmus paper is a simple and effective way to test whether a substance is an acid or a base.
• It turns red in acidic solutions and blue in basic solutions.

Explanation

• A chemical reaction is a process in which one or more substances are converted into new substances, often with a change in chemical composition and properties.
• Chemical reactions involve the breaking and forming of chemical bonds, resulting in a transformation of the original substances.

Explanation

• Leaves changing colors in the fall is an example of a chemical reaction.
• During this process, the production of chlorophyll (the green pigment) slows down, and the production of other pigments.
• Like carotenoids and anthocyanins increases, causing the leaves to change color.

Explanation

• Burning of wood is a chemical change, as it involves a chemical reaction between the wood and oxygen.
• Resulting in a change in chemical composition and the formation of new substances (ashes, carbon dioxide, water vapor, etc).

Explanation

• Hydrocarbon compounds are typically derived from fossil fuels and consist of hydrogen and carbon atoms.
• Examples include fuels like gasoline, natural gas, and propane, as well as waxes like candle wax and paraffin wax.

Explanation

• Melting of ice is a physical change, as it only involves a change in state (from solid to liquid) without a change in chemical composition.

The examples of chemical changes:

• Burning of fuel
• Explosion of firework
• Burning of wood
• Cooking of food (breakfast, lunch, dinner)
• Bursting of crackers
• Burning of wax
• Rusting of iron
• Heating sulphur with iron fillings (to produce iron sulphide)
• Digestion of food
• Respiration in living things
• Photosynthesis in plants

Explanation

When HCl is added to aqueous H₂S, the increased H+ concentration causes a shift in the equilibrium of H₂S ionization

Leading to a decrease in the ionization of H₂S due to the common ion effect

Explanation

• Carbon dioxide (gas) dissolves in water (liquid).
• It forming a gas-liquid solution.