Explanation

 Alkali metals are found in Group 1 of the periodic table.

Potassium (K) is located in Group 1, making it an alkali metal. 

Explanation

Aromatic hydrocarbons have a high carbon-to-hydrogen ratio, which leads to incomplete combustion and the production of soot when burned, resulting in a smoky flame. 

Explanation

Each molecule of water (H₂O) has 10 electrons (2 from hydrogen and 8 from oxygen).

Therefore, 1 mole of water has 10 moles of electrons.

So, 10 moles of water have 10 x 10 = 100 moles of electrons.

Explanation

Carbon dioxide (CO2) reacts with calcium hydroxide (Ca(OH)2.

It is also known as lime water to form a white precipitate of calcium carbonate (CaCO3), which turns the solution milky:

Ca(OH)2 + CO2 → CaCO3 + H2O

This reaction is often used as a test for carbon dioxide.

Explanation

• Fluorine (F) has an atomic number of 9 and an electronic configuration of 1s² 2s² 2p⁵.
• To achieve a stable electronic configuration, two fluorine atoms share one electron each to form a covalent bond.
• Resulting in a configuration similar to that of neon (Ne), which is 1s² 2s² 2p⁶.

Explanation

• A hydrogen bond is a type of intermolecular force that arises between a highly electronegative atom (such as oxygen, nitrogen, or fluorine).
• A hydrogen atom that is bonded to a highly electronegative atom.
• This interaction is typically weak compared to covalent bonds.
• But it is strong enough to influence the physical and chemical properties of molecules.

Explanation

• As you move down a group in the periodic table, the atomic size increases.
• This means that the outermost electrons are farther away from the nucleus, making it easier for the atom to gain an extra electron.
• As a result, the electron affinity decreases down a group.

Explanation

• In 1869, Dmitri Mendeleev proposed his periodic law, which states: "When the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically."
• This law allowed him to create the first periodic table, where elements were arranged in a logical order based on their atomic masses and chemical properties.

Explanation

• Diamond is a crystalline solid that has a sharp melting point.
• Meaning it melts at a specific temperature (around 4000 K) with a minimal range.

Explanation

• Gram atomic mass (GAM) is the atomic mass of an element expressed in grams.
• It represents the mass of one mole of atoms of that element.