Enviro Chapter 5 Study Cards

Question 1

LD50

Answer 1

“LD” stands for “lethal dose”
and the “50” represents 50%. LD50 is the amount of a substance that
causes 50% of a group of test animals to die if they are given a
specified dose of the substance all at once.

Question 2

heavy metals

Answer 2

They are called heavy metals because they have a density of 5 g/cm3 or more.

Question 3

sulfur dioxide

Answer 3

Sulfur dioxide (SO2(g)) is a major air pollutant that forms both smog and
acid rain. Sulfur dioxide and other oxides of sulfur form when oxygen combines
with sulfur. The major source of sulfur dioxide is industrial processes.

Question 4

nitrogen oxides

Answer 4

Nitrogen oxides (NOx(g)) form mainly from combustion in vehicles.

Question 5

carbon monoxide

Answer 5

Carbon monoxide is called the silent killer because it is a colourless and
odourless gas. When chemicals containing carbon burn, they produce
carbon dioxide or carbon monoxide.

Question 6

ozone

Answer 6

Ozone (O3(g)) is an odourless, colourless gas composed of three oxygen
atoms. At ground level, it forms from reactions between oxygen, nitrogen
oxides, and compounds called volatile organic compounds (VOCs),

Question 7

greenhouse effect

Answer 7

The atmospheric gases that trap
heat are called greenhouse gases. Water vapour, carbon dioxide, methane,
and nitrogen oxides are all greenhouse gases.
figure 2.15`

Question 8

enhanced greenhouse effect

Answer 8

The enhanced greenhouse effect results from the greater
concentration of gases trapping even more heat. In turn, this increases
overall temperatures on Earth. This temperature increase worldwide is
called global warming.

Question 9

Chlorofluorocarbons

Answer 9

These chemicals move slowly from the lower atmosphere where we use them,
up into the upper atmosphere. There, UV radiation breaks them down into
substances, such as chlorine, that destroy ozone.