Define the following terms and give one example of each. (i) system; (ii) tissue. (b) State three properties of metals. (c) (i) Define mass number of an atom. (ii) Name the two main particles in the nucleus of an atom.

Here are the answers to your questions:

I. work;
Work is done when a force causes a displacement of an object in the direction of the force. It is calculated as the product of force and displacement.

II. mechanical advantage.
Mechanical advantage is the ratio of the output force (load) to the input force (effort) in a machine. It indicates how much a machine multiplies the force applied to it.

(ii) Name one alloy and its composition.

• Brass: An alloy composed primarily of copper and zinc.

6. (a) Define the following terms and give one example of each.

(i) system;
A system is a group of interacting or interdependent elements forming a complex whole.
Example: The solar system (planets, sun, moons) or the digestive system (organs working together).

(ii) tissue.
A tissue is a group of similar cells that work together to perform a specific function.
Example: Muscle tissue (for movement) or nervous tissue (for transmitting signals).

6. (b) State three properties of metals.
i. Metals are generally good conductors of heat.
ii. Metals are generally good conductors of electricity.
iii. Metals are typically malleable (can be hammered into sheets).
iv. Metals are typically ductile (can be drawn into wires).
v. Metals usually have a lustrous (shiny) appearance.
vi. Metals generally have high melting and boiling points.

6. (c) (i) Define mass number of an atom.
The mass number of an atom is the total number of protons and neutrons in its nucleus. It represents the approximate atomic mass of the atom.

6. (c) (ii) Name the two main particles in the nucleus of an atom.
I. Protons
II. Neutrons