science end of year exams

Question 1

What is a force?

Answer 1

A force is a push or pull that can change the motion of an object.

Question 2

What is the unit of force in the International System of Units (SI)?

Answer 2

Newton (N).

Question 3

What is friction?

Answer 3

Friction is the force that opposes the motion of objects that are in contact.

Question 4

What is gravity?

Answer 4

Gravity is the force that attracts two bodies towards each other.

Question 5

How do you calculate weight?

Answer 5

Weight is calculated by multiplying mass by the acceleration due to gravity (Weight = Mass x Gravity).

Question 6

What is the difference between balanced and unbalanced forces?

Answer 6

Balanced forces produce no change in the motion of an object, while unbalanced forces cause a change in motion.

Question 7

What is tension?

Answer 7

Tension is the force exerted by a string, rope, or cable when it is pulled tight by forces acting from opposite ends.

Question 8

What is air resistance?

Answer 8

Air resistance is a type of friction that acts on objects as they move through the air.

Question 9

What is a resultant force?

Answer 9

A resultant force is the single force that represents the combined effect of all the forces acting on an object.

Question 10

What is the formula for calculating work done?

Answer 10

Work = Force x Distance (W = F x d).

Question 11

What is the main function of the digestive system?

Answer 11

To break down food into smaller molecules that can be absorbed into the bloodstream.

Question 12

What enzyme is found in saliva?

Answer 12

Amylase

Question 13

What is the role of the stomach in digestion?

Answer 13

The stomach uses acid and enzymes to break down food into a semi-liquid form called chyme.

Question 14

What are villi and where are they found?

Answer 14

Villi are small, finger-like projections found in the small intestine that increase the surface area for absorption.

Question 15

What is the function of the liver in digestion?

Answer 15

The liver produces bile, which helps break down fats

Question 16

What is the role of the large intestine?

Answer 16

To absorb water and salts from the material that has not been digested as food, and to form and store feces.

Question 17

What is peristalsis?

Answer 17

Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract.

Question 18

What is the function of the pancreas in digestion?

Answer 18

The pancreas produces digestive enzymes and bicarbonate, which are released into the small intestine to aid in digestion

Question 19

What are the main parts of the digestive system?

Answer 19

Mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.

Question 20

How does the body use nutrients absorbed from digestion?

Answer 20

Nutrients are used for energy, growth, and cell repair.

Question 21

What is the main function of the respiratory system?

Answer 21

To exchange gases, primarily oxygen and carbon dioxide, between the blood and the air.

Question 22

What is the diaphragm?

Answer 22

A dome-shaped muscle that plays a key role in breathing by contracting and relaxing to change the pressure in the chest cavity.

Question 23

Where does gas exchange occur in the lungs?

Answer 23

In the alveoli.

Question 24

What is the trachea?

Answer 24

The trachea, or windpipe, is the tube that connects the larynx to the bronchi, providing a passage for air to enter the lungs.

Question 25

What are bronchi?

Answer 25

The bronchi are the two main passages that direct air into the lungs.

Question 26

What role do the cilia in the respiratory system play?

Answer 26

Cilia are hair-like structures that move mucus and trapped particles out of the lungs.

Question 27

What is the function of the nasal cavity in respiration?

Answer 27

To filter, warm, and humidify the air we breathe.

Question 28

What is the larynx commonly known as?

Answer 28

The voice box.

Question 29

What muscle movements cause inhalation?

Answer 29

The diaphragm contracts and moves downward, and the rib muscles contract to expand the chest cavity.

Question 30

What is thermal decomposition?

Answer 30

Thermal decomposition is the process of breaking down a chemical compound into simpler substances using heat.

Question 31

Give an example of a thermal decomposition reaction.

Answer 31

The decomposition of calcium carbonate (CaCO₃) into calcium oxide (CaO) and carbon dioxide (CO₂) when heated.

Question 32

What is an example word equation for thermal decomposition?

Answer 32

oxygen → carbon dioxide + water

Question 33

Why is thermal decomposition important in industry?

Answer 33

It is used in processes such as the production of lime from limestone and the extraction of metals from ores.

Question 34

How does the stability of a compound affect its thermal decomposition?

Answer 34

More stable compounds decompose at higher temperatures.

Question 35

What is the decomposition temperature?

Answer 35

The specific temperature at which a compound starts to decompose.

Question 36

What is a catalyst, and how can it affect thermal decomposition?

Answer 36

A catalyst is a substance that speeds up a chemical reaction without being consumed, and it can lower the temperature needed for thermal decomposition.

Question 37

What is an endothermic reaction in the context of thermal decomposition?

Answer 37

An endothermic reaction absorbs heat from the surroundings, which is typical in thermal decomposition processes.

Question 38

What is a chemical indicator?

Answer 38

A chemical indicator is a substance that changes color in the presence of an acid or a base.

Question 39

What is universal indicator?

Answer 39

Universal indicator is a mixture of dyes that shows a gradual color change over a wide range of pH values to indicate the strength of acids and bases.

Question 40

What is the pH range for acidic solutions?

Answer 40

pH 0-6.

Question 41

What is the pH range for basic (alkaline) solutions?

Answer 41

pH 8-14.

Question 42

What is the pH of a neutral solution?

Answer 42

7