Analyze Element X (Period 3, Group VI) and its compound with Sodium. Also, differentiate density and relative density and apply Archimedes' principle.

$$\text{Relative density} = \frac{25}{12} \approx 2.083$$

The relative density of the object is $\boxed{\text{2.08}}$.

c)

(i) Two functions of the mammalian skeleton:

• Support for the body.
• Protection of vital internal organs.

(ii) Type of vertebrae found in each region:
I. neck region: Cervical vertebrae
II. tail region: Caudal vertebrae
III. abdominal region: Lumbar vertebrae

d)

(i) Biotechnology is the use of living organisms or their products to create or modify products or processes for specific uses.

(ii) Three applications of biotechnology:

• Production of vaccines and antibiotics
• Genetic engineering of crops for improved traits
• Gene therapy for treating genetic diseases

7.

a)

(i) A mixture is a substance containing two or more different substances that are physically combined and not chemically bonded. The components retain their individual properties.

(ii) Most appropriate method to separate:
I. water and palm oil: Decantation or using a separating funnel.
II. sodium chloride and water: Evaporation or distillation.

b)

(i) One instrument used in detecting radioactive emissions: Geiger-Müller counter.

(ii) How each radiation is affected by a magnetic field:
I. $\alpha$-particles: Deflected (positively charged).
II. $\beta$-particles: Deflected in the opposite direction to $\alpha$-particles (negatively charged).
III. $\gamma$-rays: Not deflected (no charge).

c)

(i) Two structures found in plant cells only:

• Cell wall
• Chloroplasts

(ii) Two structures found in both animal and plant cells:

• Cell membrane
• Nucleus

d)

(i) Homeostasis is the maintenance of a stable internal environment in an organism despite changes in external conditions.

(ii) Three processes in the water cycle that take water into the atmosphere:

• Evaporation
• Transpiration
• Sublimation