the atmosphere and air around us Flashcards
1
Q
what is an atmosphere?
A
the earth is surrounded by a thin layer of air called atmosphere
2
Q
what is air?
A
Air is the mixture of several gases which have been physically combined together
3
Q
name 2 main gases in air
A
nitrogen, oxygen
4
Q
other gases that are present in smaller amounts of air are?
A
carbon dioxide, noble gases
5
Q
3 main noble gases are?
A
argon, helium, neon
6
Q
name all the 5 noble gases
A
argon helium neon krypton xenon
7
Q
argon, neon, krypton and xenon are elements/molecules/compounds?
A
argon, neon, krypton and xenon are elements
8
Q
nitrogen and oxygen are an elements/molecules/compounds?
A
nitrogen and oxygen are molecules. N2, O2
9
Q
water vapor and carbon dioxide are elements/molecules/compounds?
A
water vapor and carbon dioxide are compounds
10
Q
nitrogen percentage
A
78 %
11
Q
oxygen percentage
A
21 %
12
Q
carbon dioxide percentage
A
0.04 %
13
Q
noble gases percentage
A
0.96 %
14
Q
water vapor percentage
A
variable
15
Q
define photosynthesis
A
photosynthesis is the process whereby a plant manufactures their own food
16
Q
what happens during photosynthesis?
A
during photosynthesis, the chlorophyll present in the leaves trap in energy from sunlight to use it to convert water and carbon dioxide into oxygen and glucose .
17
Q
what does the plant use to carry out photosynthesis?
A
sunlight, water, carbon dioxide and minerals from the soil
18
Q
what energy does the glucose contain and what kind of change is photosynthesis?
A
the glucose contains chemical energy. the process of photosynthesis is an example of a chemical change, new products are formed and the change is irreversible
19
Q
what is the product of photosynthesis?
A
the product of this process is food for the plant in form of glucose and oxygen gas
20
Q
word equation of photosynthesis
A
carbon dioxide +
water
–chlorophyll
sunlight ———>
glucose + oxygen.
21
Q
define respiration
A
respiration is a biochemical process during which organisms obtain energy
22
Q
what happens during respiration?
A
during respiration, glucose is broken down in the presence of oxygen.
23
Q
define combustion?
A
combustion is a chemical reaction between fuel and oxygen
24
Q
what is complete combustion?
A
complete combustion is when fuel burns in sufficient amount of oxygen and forms water and carbon dioxide
25
what is in incomplete combustion?
incomplete combustion is when fuel is burned in insufficient amount of oxygen and forms carbon monoxide and water
26
what is carbon?
carbon is an element present in all living organisms
27
where is carbon present in other than living organisms?
it is present in air, rocks and soil
28
how is carbon returned in the atmosphere?
when fossil fuels are burnt carbon is returned in the atmosphere as carbon dioxide
29
define carbon cycle
the carbon cycle comprises of 3 processes namely, photosynthesis, combustion and respiration. (decomposition) these 3 processes maintain the level of carbon dioxide in the atmosphere almost constant.
30
define greenhouse gases
greenhouse gases are gases that retain heat energy in the atmosphere
31
define greenhouse effect
when greenhouse gasses retain an excess of heat energy in the atmosphere it is known as greenhouse effect
32
importance of greenhouse gases
they keep the earth's surface warm for survival of human beings
33
the 2 main GHGs are?
methane and carbon dioxide
34
what is methane and carbon dioxide responsible for?
they are the main cause of global warming
35
name the activities that release methane
animal breeding and farming releases methane
decaying of wastes emits methane
36
name the activities that release carbon dioxide
factories realease much carbon dioxide through their chimneys
when people burn garbage it produces carbon dioxide
badly maintained vehicles emit carbon dioxide in excess
deforestation contributes to emission of carbon dioxide
37
how does deforestation cause emission of carbon dioxide
when trees are cut down and burnt, their stored carbon is released into the air as carbon dioxide
38
define global warming
global warming is the increase of earth's average temperature due to the presence of increasing amount of GHGs in the atmosphere
39
how is global warming caused?
an increase of greenhouse gases retain excess heat energy in the atmosphere, resulting in global warming
40
causes of global warming
production of electricity in power stations
burning of garbage
livestock farming
all means of transportation
decaying of organic wastes in landfills
41
define climate change
climate change is the changes of weather patterns over time caused by increasing amounts of GHGs and other pollutants
42
differentiate between climate change and global warming
global warming focuses on the increase of the earth's average temperature due to increasing amounts of GHGs in the atmosphere
where as
climate change focuses on the changes of the weather pattern over time due to increasing amounts of GHGs and other air pollutants.
43
examples of climate change
abnormal increase in temperature leading to severe drought
melting of glaciers
flooding and rising of sea levels
increase in frequency and intensity of cyclones
coral breaching
decreased rainfall
44
what has led to climate change?
an increase in the amount of greenhouse gases and other pollutants has led to climate change
45
measures to combat climate change
avoid burning of fossil fuels thus reducing the amount of carbon dioxide formed in the atmosphere
save electrical energy by using economic blubs
plant trees to absorb more carbon dioxide from the atmosphere
recycling of plastic waste
use alternate sources of energy like solar energy and wind energy
46
name the air pollutants
carbon monoxide, oxides of nitrogen, sulfur dioxide, chlorofluorocarbon and smokes are considered air pollutants
47
what is carbon monoxide?
carbon monoxide is a colourless and odourless gas
48
how is carbon monoxide formed?
carbon monoxide is produced from incomplete combustion
49
list a few examples of incomplete combustion
burning kerosene in a closed room (operating portable generators in a closed room)
using charcoal grills in a closed garage
operating gas water heaters in an enclosed bathroom with no proper ventilation
internal combustion engines of vehicles
50
what are the effects of carbon monoxide ?
carbon monoxide is poisonous as it reduces oxygen transport by haemoglobin in the blood
51
symptoms of carbon monoxide poisoning
headache, vomiting, loss of consciousness and death
52
CO + HB ------> ?
CARBOXYHAEMOGLOBIN
53
what is sulfur dioxide?
sulfur dioxide is a colourless gas with a sharp and irritating smell
54
how is sulfur dioxide formed?
sulfur dioxide is formed when fossil fuels are burnt because fossil fuels contain sulfur which on combustion combines with oxygen to form sulfur dioxide
55
list where sulfur dioxide is released
chimneys of factory burning fuels
(coal fired power stations)
exhaust pipes of motor vehicles
56
where is sulfur dioxide naturally released?
during volcanic eruptions
57
what are the effects of sulfur dioxide in the environment?
sulfur dioxide
reacts with water vapour and oxygen to form sulfuric acid,
this sulfuric acid then dissolves in clouds causing rain water to become acidic
58
how is acid rain formed?
acid rain is formed when sulfur dioxide reacts with water vapour and oxygen to form sulfuric acid, this acid then dissolves in clouds making rain water acidic
59
effects of sulfur dioxide in health
affects the respiratory system
causes coughing
aggravates conditions such as asthma and bronchitis
irritates eyes and skin as in dissolves in moisture to form acid
60
name the oxides of nitrogen
nitrogen monoxide NO
nitrogen dioxide NO2
61
how is oxides of nitrogen formed ?
oxides of nitrogen comes mostly from internal combustion engines of vehicles where oxygen and nitrogen from the air react at high temperatures prevailing in the engines
oxides of nitrogen also form during lightning
62
How is lightning formed by oxides of nitrogen ?
the very high temperature in the vicinity of a lightning bolt causes
oxygen and nitrogen in the air to react and form oxides of nitrogen
63
what are the effects of oxides of nitrogen in the environment ?
oxides of nitrogen react with water vapour and oxygen in the air to form nitric acid, thus causing acid rain
64
what are the effects of oxides of nitrogen on health ?
they damage the lungs and cause respiratory problems
they irritate the eyes and skin
detrimental effect on human health
65
what is smoke ?
smoke is an unwanted by-product of fires
66
what does smoke consist of ?
it consists of tiny suspended solid particles which is mainly composed of soot and ash
67
what poisonous gases does smoke contain ?
it contains carbon monoxide and acidic gases (sulfur dioxide and oxides of nitrogen)
68
list sources of smoke
chimneys of factories
burning of garbage
burning of cigarette
exhaust pipes of vehicles
barbecue grills
spreading fire
69
what are effects of smoke on the health ?
reduced oxygen content causing suffocation
smoke contains carbon monoxide which leads to headache loss of consciousness and death
smoke contains acidic gases like sulfur dioxide and oxides of nitrogen which causes irritation of eyes, skin burns and damage of the lungs
70
what is chlorofluorocarbon CFC ?
chlorofluorocarbons are compounds which are made up of Carbon, Fluorine and chlorine.
71
where are chlorofluorocarbons used ?
they are used as coolants in refrigerators and air conditioner
propellants for aerosols, cans (sprays)
cleaning agents since they remove grease and dirt
72
name the layer that surrounds the earth's atmosphere and give its function.
the layer surrounding the earth's atmosphere is called the ozone layer and it helps to absorb Ultraviolet (UV) rays from the sun, preventing them from entering the atmosphere
73
why is ultraviolet rays harmful ?
ultraviolet rays causes skin diseases, skin cancers and eye diseases (cataract)
74
how is the ozone layer depleted ?
CFCs (Chlorofluorocarbon) break down in the upper atmosphere to form chlorine atoms which react with ozone layer thus depleting and making holes in it
75
what are the effects of Ultraviolet rays ?
UV rays from the sun enter the atmosphere and increase the risk of skin cancers and eye diseases
76
measures to prevent air pollution
sulfur dioxide from wastes gases of factories can be removed by passing the waste gases through powdered calcium carbonate (limestones)
catalytic convertors are devices which are found in exhaust systems, they convert harmful gasses into less harmful ones. carbon monoxide is converted into carbon dioxide and oxides of nitrogen is converted into nitrogen
people should be encouraged to use public transportation and to make use of carpooling in order to reduce the amount of fossil fuel burnt
CFCs should be replaced by other substances which do not deplete the ozone layer
burning waste at home should be avoided as it produces a lot of smoke and toxic gases
reguglar servicing of vehicles should be done to prevent emission of large amounts of smoke
filters should be placed on factory chimneys
spraying water around stone crushing plants
avoid spraying pesticides and insecticides on windy days
use renewable sources of energy
77
what sectors mostly cause much air pollution ?
construction, agriculture, transport sectors cause much air pollution
78
what is water pollution ?
water pollution id the discharge of harmful substances directly discharged or indirectly discharged into lakes, streams, rivers and oceans
79
causes of water pollution
sewage from households, offices and industries
fertilisers from agriculture
industrial wastes
oil spillage from ships
garbage dumping
80
what is eutrophication?
when excess of fertilizers is washed into lakes or river it increases the growth if algae thus covering the surface of the water, this prevents sunlight from reaching aquatic plants, then plants die and decompose depleting the oxygen in the water, consequently fish and other aquatic animals die
