Correct Answer: B. 1

Explanation

The valency of an element is determined by the number of electrons it gains or loses to achieve a stable electron configuration. For an element with the electronic configuration 2, 8, 7, the outermost shell (valence shell) has 7 electrons. To achieve stability, it needs 1 more electron to fill the outermost shell, so its valency is 1.

Correct Answer: B) hooks and suckers

Explanation

A tapeworm is a type of parasite that lives in the intestine of its host. The question is asking how a tapeworm attaches itself to the intestine of its host. The options are neck and sucker, hooks and suckers, rostellum and suckers, proglottis and neck, and rostellum, hooks and suckers. The correct answer is hooks and suckers. Tapeworms have hooks and suckers on their head, which they use to attach themselves to the intestinal wall of their host. The hooks help to anchor the tapeworm while the suckers help to create a seal between the tapeworm and the intestinal wall. It is important to note that tapeworms can cause health problems in their hosts and should be treated by a medical professional. Additionally, it is important to practice good hygiene and food safety to prevent tapeworm infections. Overall, tapeworms use hooks and suckers to attach themselves to the intestine of their host, causing health problems if left untreated.

Correct Answer: C) artificial radioactivity

Explanation

The given equation is: \(^{14}_{7}N + ^{4}_{2}He \rightarrow ^{17}_{8}O + ^{1}_{1}P\). This equation represents a nuclear reaction in which a nitrogen-14 nucleus combines with an alpha particle (helium-4 nucleus) to form an oxygen-17 nucleus and a proton.

This type of reaction does not fall under the category of nuclear fusion or fission. Innuclear fusion, two or more lighter nuclei come together to form a larger nucleus, usually accompanied by the release of energy. Innuclear fission, a heavier nucleus splits into two or more lighter nuclei, again accompanied by the release of energy.

However, the given reaction involves the bombardment of a stable nucleus with a particle to produce a new nucleus and another particle. This process is known asartificial radioactivity, which is the correct answer (Option C). Artificial radioactivity is induced by scientists in a laboratory setting, as opposed to natural radioactivity, which occurs spontaneously in nature.

Correct Answer: D. lending out money from customers deposits

Correct Answer: D. arrest

Correct Answer: C. 184πcm²

Correct Answer: B. 72πcm²

Correct Answer: A. Deed

Explanation

a) Entrepot trade is the importation of goods into a country with the intention of re-exporting them to other countries

b) i) A bill of lading is a contract between the exporter and the shipowner for the carriage of goods to their destination while a consignment note is a contract of domestic carriage of goods when the seller uses an independent carrier.

ii) The purpose of a bill of sight is to enable customs officers to carry out the inspection and valuation of goods when the bill of lading has not yet arrived.

c) i) It increases the cost of marketing products and thus the price of the products

ii) Certain advertisements mislead customers through false or exaggerated statements about the products

iiI) persuasive advertising induces customers to buy what they do not really need.

iv) Certain advertisements by big companies aim at driving away small firms from the business.

v) Advertisements of certain products encourage customers to use harmful products

vi) Advertisement may create false personality images and moral exploitation of the youth/Advertisement could be harmful to the society because of the use of decent language and improper dress

vii) Successful advertisement will lead to monopoly.

Correct Answer: A) carbon

Explanation

In the electrolysis of brine (a solution of saltwater), the anode is made ofcarbon. The anode is the positive electrode in an electrolytic cell, where oxidation occurs. Brine electrolysis is the process of passing an electric current through a saltwater solution to produce various chemicals, such as chlorine gas, hydrogen gas, and sodium hydroxide.

During the electrolysis of brine, the following reactions occur at the anode and cathode:

At the anode (oxidation):

\(2Cl^?(aq) ? Cl_2(g) + 2e^?\)

At the cathode (reduction):

\(2H_2O(l) + 2e^? ? H_2(g) + 2OH^?(aq)\)

The choice of carbon as the anode material is important because it is a good conductor of electricity and is relatively inert. This means it doesn't easily react with other chemicals in the cell, ensuring that the desired chemical reactions take place efficiently.

Other materials mentioned in the options, such as platinum, zinc, and copper, are not suitable for use as anodes in the electrolysis of brine. Platinum is a good conductor, but it is expensive and can be corroded by the chlorine gas produced. Zinc and copper are also good conductors, but they are reactive metals and can dissolve or corrode in the electrolytic process, which is not desirable.