What is meant by ...

Refrigeration cycle in the refrigerator

It is a closed and repeated thermal process in which heat is extracted from inside the refrigerator to the outside using eco-friendly freons

Heat of dissolution

it is the amount of heat absorbed or released when dissolving a specific quantity of solute in a known volume of solvent to form a solution

Exothermic dissolution

A physical change which heat energy is released during dissolving.

Endothermic dissolution

A physical change in which heat energy is absorbed during dissolving.

law of conservation of energy

Energy is neither destroyed nor created, but can be transformed from one form to another

Exothermic reactions

Reactions that release thermal energy to the surroundings as a product of the reaction, causing the temperature of the surroundings to rise

Endothermic reactions

Reactions that require the absorption of thermal energy from the surroundings, causing the temperature of the surroundings to decrease.

Fuel

It is a flammable material used to produce thermal energy (heat) as a result of an exothermic reaction.

Calorific value of fuel

It is the amount of energy produced from the combustion of 1 g of fuel in excess of oxygen gas

Combustion

It is the process of the combination of fuel with oxygen which is usually accompanied by the emission of light, heat, or both

Ignition point

It is the temperature at which the material begins to ignite

Spontaneous combustion

It is the ignition of materials without the presence of an external source of heat

Oxidation process

A chemical process in which the percentage of oxygen increases in the substance or the percentage of hydrogen decreases in it

Reduction process

A chemical process in which the percentage of oxygen decreases in the substance or the percentage of hydrogen increases in it

Reducing agent

It is the substance that gives hydrogen to, or takes oxygen away from another substance during the chemical reaction

Oxidizing agent

It is the substance that gives oxygen to, or takes hydrogen away from another substance during a chemical reaction.

Net force

The total force in magnitude and direction resulting from the effect of a number of forces acting on an object

Newton’s first law (Law of inertia)

The object keeps its state of rest or motion at a constant velocity in a straight line, unless acted upon by external unbalanced forces that change its state

Stopping time

The time taken for the moving object to stop

Stopping distance

The distance traveled by the moving object during the stopping time.

Acceleration (a)

the change in the velocity of the object per unit time OR the rate of change of the velocity.

Newton’s second law

If a net force (F) acts on an object of mass (m), it causes the object to have an acceleration (a) in the same direction as the net force

Newton’s third law

For every action, there is an equal and opposite reaction

The machine

It is a means used by man to save time, effort, or both while performing tasks

The lever

A rigid (straight or curved) bar that moves around a fulcrum (axis of rotation) (F) and is acted upon by a effort (E) and a load (L)

Effort arm

The distance between the applied effort and the fulcrum

Load arm

The distance between the load and the fulcrum

Moment (torque) of effort

The product of multiplying the effort by its arm

Moment (torque) of load

The product of multiplying the load by its arm

Law of levers

The product of multiplying the effort by its arm equals the product of multiplying the load by its arm

Reproduction

The cell

Somatic cells

Gonads

Gametes

Mitosis (Mitotic division Equational division)

Meiosis (Meiotic division Reductional division)

The crossing-over phenomenon

The cancerous (malignant) tumor

Asexual reproduction

Vegetative reproduction

Sexual reproduction

Fertilization

Zygote

Tadpole stage

Flower

Bract

Inflorescence

Peduncle

Receptacle

Naked flowers

Hay fever

Typical flower

Bisexual flower

Unisexual flower

Pollination

Self-pollination

Cross-pollination

Fertilization in the flower

Zygote