Correct Answer: B. oil prices have fallen drastically

Correct Answer: A. an acidic oxide

Explanation

When sulphur burns in air, it reacts with oxygen to form sulphur dioxide (SO2):

S(s) + O₂(g) → SO₂(g)

Sulfur is a non-metal. Oxides of non-metals are generally acidic in nature. Sulfur dioxide (SO₂) reacts with water to form sulfurous acid (H₂SO₃), which confirms its acidic nature:

SO₂(g) + H₂O(l) ⇌ H₂SO₃(aq)

Therefore, sulphur burns in air to form an acidic oxide.

The correct answer is A.

Correct Answer: A. 2.4 x\(10^{-2}cm^{-3}\)

Explanation

\(3{\alpha}= \frac{\Delta{V}}{V_1\Delta{T}}\Rightarrow \frac{\Delta{V}}{100\times40}=3\alpha\, where\, \alpha = 2 \times 10^{-6}\\ \frac{\Delta{V}}{4000}=6\times10^{-6}\Rightarrow \Delta=4\times10^3\times6\times10^{-6}= 2.4\times10^{-2}cm^{-3}\)

Correct Answer: D) mitochondria

Explanation

Energy is produced in the cell by a structure called the mitochondria. Mitochondria are known as the powerhouses of the cell as they produce energy in the form of ATP (Adenosine Triphosphate) through a process called cellular respiration. ATP is the primary source of energy that the cell uses for various processes including movement, growth, and repairing damaged cells. The nucleus is the control center of the cell that regulates cellular activities and contains genetic material in the form of DNA. The nucleolus is a small structure within the nucleus that produces ribosomes. Lysosomes are organelles that contain digestive enzymes that break down waste materials and foreign substances within the cell. In summary, energy is produced in the mitochondria, which is a vital organelle in the cell responsible for generating ATP through cellular respiration. To learn more about cellular organelles and their functions, please refer to the recommended textbooks.

Correct Answer: (B) privilege

Explanation

(a)Methods used by the pre-colonial chiefs of a country to control their subjects are:

(i) Laws, rules and regulations were used to control their subjects.

(ii) Settlement of disputes: The traditional rulers performed some judicial functions by settling disputes.

(iii) Law enforcement: Law enforcement institutions were created e.g. Age grades, masquerades, etc.

(iv) The use of ancestral spirits.

(v) Appointment of minor chiefs.

(vi) Rewards: People who have contributed to the development of their areas were rewarded with titles or distribution of land and war booty.

(vii) Customs/taboos and conventions were used to control their subjects.

(viii) Sanction and punishments were applied against law breakers e.g. banishment.

(ix) Oath taking was used to control the subjects.

Correct Answer: D. Exfoliation

Correct Answer: A. Water, carbondioxide and energy

Correct Answer: C. defend the sovereignty and territorial integrity of the country

Correct Answer: A. Joseph J. Thompson