What is amu?
ANSWER: Atomic Mass Unit (amu): “The unit used to express the relative atomic mass is called atomic mass unit (amu). It is 1/12th of the mass of one carbon atom.” On C–12 scale, the relative atomic mass of 6C12 is…
Ejaz H. Abbasi
What is relative atomic mass?
ANSWER: Relative Atomic Mass: “Relative atomic mass is the mass of an atom of an element as compared to the mass of an atom of carbon taken as 12.” We use the term relative atomic mass because the given masses…
Differentiate between ion and molecular ion.
ANSWER: ION MOLECULAR ION 1) “Those species which carry either positive or negative charge are called ions.” 2) Anions having group of atoms are more abundant than cations.3) Examples: K+, Mg2+, Al3+, O2–, CO32– etc. 1) “When a molecule loses…
Define molecular ions with examples.
ANSWER: MOLECULAR IONS: “When a molecule loses or gains an electron, it forms a molecular ion.” Formation of Molecular Ions: Molecular ions can be generated by passing high-energy electron beams or α-particles or X–rays through a substance present in gaseous…
The formation of a uninegative ion is an exothermic reaction. Explain.
ANSWER: The formation of a uninegative ion is an exothermic reaction. This is because energy is released when an extra electron enters a neutral atom and is attracted by its nucleus. B + e– ⟶ B– ∆H = Negative (Ref.…
The formation of a positive ion is an endothermic reaction. Explain.
ANSWER: The formation of a positive ion is always an endothermic reaction. The reason is that positive ion is formed by the removal of one or more electrons from the neutral atom. Since, electrons are strongly held by the nucleus,…
What are ions? Under what conditions are they produced?
ANSWER: IONS: “Those species which carry either positive or negative charge are called ions.” Examples: K+, Mg2+, Al3+, Cl–, O2–, CO32– etc. Conditions for the Formation of Ions: 1) Positive ions or cations are produced when an atom loses one…
What are macromolecules? Give an example.
ANSWER: MACROMOLECULES: “The molecules consisting of thousands of atoms are called macromolecules. Their molecular masses range from thousands to millions.” Examples: Haemoglobin is a macromolecule found in blood. It carries oxygen from our lungs to all body parts. Each molecule…
Define the term atomicity. Give examples.
ANSWER: ATOMICITY: “The number of atoms present in a molecule is called its atomicity.” The molecules may be: (Ref. An Insight Into Objective Chemsitry-11, Ch-01, Q. No. 07)
Differentiate between an ‘atom’ and a ‘molecule’.
ANSWER: ATOM: MOLECULE: (Ref. An Insight Into Objective Chemsitry-11, Ch-01, Q. No. 06)