An atom of an element is represented as 178X.

Here are the solutions to the questions:

1. An atom of an element is represented as $^{17}_{8}X$.

   • The atomic number (number of protons) is the subscript, which is 8.
   • The mass number (protons + neutrons) is the superscript, which is 17.

   a) Determine the:
   (α) Protons:
   The number of protons is equal to the atomic number.

   $$\text{Protons} = 8$$

   (β) Electrons:
   For a neutral atom, the number of electrons is equal to the number of protons.

   $$\text{Electrons} = 8$$

   (γ) Neutrons:
   The number of neutrons is the mass number minus the atomic number.

   $$\text{Neutrons} = \text{Mass number} - \text{Atomic number} = 17 - 8 = 9$$

   b) State the position of the element $X$ in (i) on the periodic table:
   The electronic configuration for an atom with 8 electrons is $1s^2 2s^2 2p^4$.
   (α) Group:
   The number of valence electrons is $2+4=6$. Therefore, the element is in Group 16 (or VIA).
   (β) Period:
   The highest principal energy level is 2. Therefore, the element is in Period 2.

2. a) Explain briefly heat transfer by conduction: Conduction is the transfer of heat energy through direct contact between particles of a substance, without any net movement of the substance itself. It occurs when vibrating particles transfer energy to adjacent particles. b) Name two other methods of heat transfer:

   • Convection
   • Radiation

3. a) Give two examples of water bodies:

   • Rivers
   • Lakes b) State two practices of humans that destroy water bodies:
   • Discharge of untreated industrial waste and sewage
   • Deforestation leading to soil erosion and sedimentation c) State two methods of conserving water bodies:
   • Implementing strict regulations on waste disposal and treating wastewater before discharge
   • Promoting afforestation and reforestation to prevent soil erosion

4. a) State three ways by which bacterial diseases are managed:

   • Administration of antibiotics
   • Vaccination to prevent infection
   • Maintaining good hygiene and sanitation practices b) Give an example of a bacterial disease:
   • Cholera