Explanation

Elements of Group IVA (Group 14) like carbon (C) and silicon (Si) have very high melting points due to strong covalent bonding.

For example, diamond (carbon) has the highest melting point among all elements.

Explanation

Abrasives are substances that wear away or remove material through friction or rubbing.

Examples of abrasives include:

Water insoluble minerals like:

• Silica (sand)
• Alumina (aluminum oxide)
• Calcium carbonate (limestone)
• Diamond

Explanation

Systematic errors are caused by faulty or improper functioning of instruments, or by a flaw in the experimental design.

These errors are consistent and repeatable, and can be identified and corrected.

Explanation

When the magnitude of Kc (equilibrium constant) is small, it indicates that the reaction mixture contains mostly reactants, and the forward reaction does not proceed very far.

Explanation

Group VIII-A, also known as the noble gases, consists of:

• Helium (He)
• Neon (Ne)
• Argon (Ar)
• Krypton (Kr)
• Xenon (Xe)
• Radon (Rn)

Explanation

• When two identical atoms share electron pairs and exert an equal force on each other, the bond formed is a non-polar covalent bond.
• This type of bond is characterized by a equal sharing of electrons, resulting in a balanced and symmetrical distribution of electrons.

Explanation

• The octet rule states that atoms tend to gain, lose, or share electrons to achieve a full outer energy level, which typically corresponds to eight electrons in the valence shell.
• This rule is a fundamental principle in chemistry and is used to explain the formation of chemical bonds and the structure of molecules.

Explanation

Joseph Priestly discovered oxygen on August 1, 1774.

The most abundant element in the Earth's crust is oxygen, making up 46.6% of Earth's mass

Explanation

Maximum molar volume is at 127°C and 1 atm = 32.84 L

Explanation