Living Things And Air

Question 1

What are the components of the atmosphere?

Answer 1

Nitrogen (78%), Oxygen (21%), Noble gases (0.9%), Water Vapour (0.07%), Carbon Dioxide (0.03%)

Question 2

What are tests that can be used to identify oxygen?

Answer 2

Burning splint test, glowing splint test

Question 3

What are the results for the tests identifying oxygen?

Answer 3

When a burning splint is put into a test tube of oxygen, it will burn more brightly. When a glowing splint is put into a test tube of oxygen, it will start burning.

Question 4

What are tests that can be used to identify carbon dioxide?

Answer 4

hydrogencarbonate indicator test, limewater test

Question 5

What are the results for the tests identifying carbon dioxide?

Answer 5

When hydrogencarbonate indicator is dropped into a test tube of carbon dioxide, it turns from red to yellow. When limewater is dropped into a test tube of carbon dioxide, it turns from colourless to milky.

Question 6

What is an element?

Answer 6

A type of molecule made up of only one type of atoms.

Question 7

What is a compound?

Answer 7

A type of molecule made up of more than one type of atoms.

Question 8

What is the difference between elements and compounds?

Answer 8

Elements appear in the periodic table. Compounds don’t.

Question 9

What are the characteristics of carbon dioxide?

Answer 9

It is colourless and odourless. It does not burn or support burning.

Question 10

What are the characteristics of oxygen?

Answer 10

Oxygen is colourless and odourless. It does not burn but it supports burning.

Question 11

What test can be used to identify water or water vapour?

Answer 11

Dry Cobalt Chloride paper

Question 12

What is the result for the test identifying water or water vapour?

Answer 12

The dry cobalt chloride paper turns from blue to pink when it is in contact with water or water vapour.

Question 13

What will happen if hydrogencarbonate indicator is dropped into a test tube of oxygen?

Answer 13

It will remain red with no colour change.

Question 14

What will happen if a burning or glowing splint is put into a test tube of carbon dioxide?

Answer 14

The splint will go out.

Question 15

What will happen if limewater is mixed with oxygen?

Answer 15

The limewater will remain colourless.

Question 16

Which gas is used to combine with fuels and burn at very high temperatures to cut metals?

Answer 16

Oxygen

Question 17

What is dry ice and what is its effect and usage?

Answer 17

Dry ice is solid carbon dioxide that sublimes to carbon dioxide at room temperature. It is used to create a fog effect on stage.

Question 18

What is liquid nitrogen used for?

Answer 18

Liquid nitrogen is used to store living tissues or cells.

Question 19

Why is argon used to fill light bulbs?

Answer 19

Argon is unreactive. It slows oxidation of the wire inside the lightbulb and the evaporation of the wire caused by heating, so it extends the lightbulb’s lifespan.

Question 20

What are the two gases used to fill balloons and which of them is flammable?

Answer 20

Helium and Hydrogen are used to fill balloons, in which Hydrogen is flammable. Helium is an inert (unreactive) gas.

Question 21

Which gas is used for filling advertising lights?

Answer 21

Neon

Question 22

What is the by-product of photosynthesis?

Answer 22

Oxygen

Question 23

What is the difference between glucose and starch?

Answer 23

Glucose is a form of food in the plant that is used immediately, and starch can be converted from glucose for temporary storage.

Question 24

What is the word equation of photosynthesis?

Answer 24

Light energy absorbed by chlorophyll
Carbon dioxide + water ———|______———> glucose+oxygen

Sorry that’s really bad I couldn’t type the arrow

Question 25

What is the chemical equation of photosynthesis?

Answer 25

Light energy absorbed by chlorophyll 6CO2+6H2O ——————|________—————> C6H12O6+6O2 Note: the numbers for CO2, H2O, C6H12O6, and O2 should be written at the bottom right-hand side of the letters,

Question 26

Which substances/energy sources are vital for photosynthesis?

Answer 26

Light energy, carbon dioxide, water, chlorophyll in the leaves of the plant

Question 27

Where does the plant get carbon dioxide and water from?

Answer 27

The plant gets carbon dioxide from the air and water from the soil.

Question 28

When testing for the presence of starch in a leaf provided with necessary conditions for photosynthesis to take place, what is the purpose of having the leaf boil in hot water for 10 minutes?

Answer 28

Boiling the leaf destroys the cell membranes.

Question 29

Which solution should we use to show that there is starch in a leaf and how?

Answer 29

Iodine solution. Iodine solution turns from brown to blue-black when in contact with starch.

Question 30

What are the reactants in respiration?

Answer 30

Glucose and oxygen

Question 31

What are the products of respiration and what are they used for?

Answer 31

Carbon dioxide and water, they are converted to useful energy forms

Question 32

Write down facts about a) photosynthesis and b) respiration. 1. Where do they take place? 2. What are the reactants? 3. What are the products? 4. When do they usually take place?

Answer 32

1. a) only plants b) plants and animals 2. a) carbon dioxide and water b) glucose and oxygen 3. a) glucose and oxygen b) carbon dioxide and water 4. a) in daytime b) in both daytime and nighttime

Question 33

What is the importance of photosynthesis?

Answer 33

It keeps the oxygen and carbon dioxide balanced and provides food for animals in the food chain.

Question 34

Does the plant have a net gas intake when exposed to sunlight?

Answer 34

Yes. Under sunlight, photosynthesis and respiration are taking place at the same time, but photosynthesis has a higher rate. Therefore, there is a net carbon dioxide intake in daytime.

Question 35

Compare the following aspects of inhaled air and exhaled air. 1) oxygen percentage 2) CO2 percentage 3) temperature 4) water vapour concentration

Answer 35

Inhaled air/exhaled air: 1) 21%/16% 2) 0.03%/4% 3) lower/higher 4) less/saturated

Question 36

What do we use to test the concentration of water vapour in inhaled and exhaled air and how?

Answer 36

Dry cobalt chloride paper is used. The paper turns from blue to pink when exposed to water vapour. The paper turns to pink much faster when we breathe on it than when it is left outside exposed to inhaled air. Therefore, we can conclude that there is more water vapour in exhaled air than inhaled air.

Question 37

Describe the procedural steps to collect exhaled air.

Answer 37

1. A gas jar is completely immersed in a water trough. 2. The gas jar is placed so that the opening of the jar is touching the bottom of the water trough. 3. A straw is inserted into the opening of the jar. 4. Air is blown out into the jar via the straw. 5. The process is repeated until the gas jar is filled with exhaled air.

Question 38

Where does human gas exchange take place?

Answer 38

Air sacs

Question 39

Describe the pathway of inhaled air.

Answer 39

Nasal cavity, trachea, bronchi(bronchus is singular), bronchioles, air sac

Question 40

What are three harmful substances found in cigarettes?

Answer 40

Carbon monoxide (causes less oxygen in blood, fainting, or death), Nicotine (an oily substance that causes addiction), and tar (a brown sticky substance that sticks to the inner wall of the trachea)

Question 41

Why are the frogs’ lungs not as effective as humans’ lungs?

Answer 41

The frogs’ lungs only have a small number of air sacs, which makes gas exchange inefficient. On the other hand, human lungs have millions of air sacs at the end of bronchioles that take up a total surface area of one tennis court, providing a very large area available for gas exchange, which makes gas exchange very effective.

Question 42

What are the possible harmful effects of global warming? (Science syllabus)

Answer 42

Melting of ice at polar regions, causing flooding in low-lying areas, and climate change, causing more frequent climatic hazards (heat waves, storms and droughts) and food shortage problems.

Question 42

What are the harmful air pollutants?

Answer 42

Carbon monoxide (reduces oxygen content in blood, causing headaches, fainting, or death), sulphur dioxide and nitrogen oxides (cause irritation to breathing system and eyes), suspended particulates (causes respiratory diseases and lung diseases)

Question 44

What is the full name of AQHI?

Answer 44

Air quality health index

Question 45

How many levels are there in AQHI?

Answer 45

There are 11 levels, classified into 5 categories (low, moderate, high, very high, serious; 1-3, 4-6, 7, 8-10, and 10+) in AQHI.