1. (a) Study the table below and use it to answer the questions that follow.

Element ATOMIC N MASS N

V 10 18

W 18 39

X 15 33

Y 10 20

Z 11 23

*Note* : *N* means number✅

(i) how many neutrons are there in atom X?

(ii) Which of the atoms will readily form an ion?

(iii) Which of the atoms will form an ion with a positive charge of +3?

(iv). Indicate the-atoms that are isotopes. Explain your answer-in (a) (iv) (a) above.

(b)(i) What is a fertilizer?

(ii). State two effects of improper application of inorganic

(c) What is excretion?

(ii) Describe briefly how plants excrete each of the following substances:

(a) excess water;

(b). oxygen

(d) (i) What is meant by moss of a body?

(ii) A room of area 12 m x 14 m has a height of 5 in. If the density of air in the room is 1.32Kgm-3, calculate the mass of the air in the room.

2.(a)(i) What is food preservation?

(ii) Explain the .principles undedying. each of the following methods of food preservation:

(a) salting;

(b). canning.

(b)(i). What is a pathogen?

(ii) State three ways in which pathogens are transmitted from one-person to another.

(c)(i).-What are X-rays?

(ii)-State three dangers associated with over exposure to X-rays.

(d) Write the structural formulae of each of the following chemical compounds:

(i) Ethanoic acid;

(ii) 2, 2 — dimethlbutane;

(iii) 3, methyl pent — 2 — ene;

(iv) 2, methylbutan — 2 — ol.

3.(a) Explain the mechanism by which the body of a mammal cools when the temperature rises.

(b) (i). What is a direct current as used in electricity?

(ii) An electric furnace operating on 200 V, uses 3 kW of power. Calculate the current that flows.

(c)(i). Name the main ore from which aluminium is extracted.

(ii) State three properties that make aluminium suitable for use as cooking utensils.

(d)(i) What is an ornamental plant?

(ii) State three maintenance practices to be adopted to ensure growth of ornamental plants.

4. (a). (1). Explain the term frequency as applied to sound waves.

(ii) A wave of wavelength 0.3 m moves at a velocity of 400 ms-1. Calculate the frequency of the wave.

(b) (I) What is poultry? (ii)State four reasons for keeping poultry.

(c) (i) Explain the term population density.

(ii) State three effects of high population density on the environment.

(d) The engine of a car is left running in an enclosed garage. Explain why the fumes from the engine could lead to the death of a person in this enclosed garage

5.(a) (i). Distinguish between normal salt and acid salt.

(ii) Give one example of each type of salt named in (a) (i) above.

(b) (i). Explain the term drenching as applied to animal production.

(ii) State three ways in which drenching is important in animal production.

(c) (i). Explain the following genetic terms:

(a) dominant character

(b). enotype

(ii) The offspring of a black rabbit and white were all found to be black.

With the aid of an appropriate crosses, illustrate the observation.

(d) Explain this observation. A passenger sitting in a bus tends to fall backward when the bus moves suddenly.

6.(a) (i). What is crop rotation?

(ii). State three advantages of crop rotation.

(b). Name the kingdom to which each of the following organisms belong:

(i). Maize

(ii). Bacterium

(iii). Mushroom;

(iv) Lizard.

(c) (i). What is a transistor?

(ii) Explain how a transistor behaves as a switch.

(d) Magnesium ribbon of mass 4.0 g is placed in dilute hydrochloric acid contained in a beaker. Calculate the number of moles of hydrochloric acid that would be required to react completely with the ribbon. [Mg = 24, H= 1, CI = 35.5]