<span>In the 19th century, scientists realized that gases in the atmosphere cause a "greenhouse effect" which affects the planet's temperature. These scientists were interested chiefly in the possibility that a lower level of carbon dioxide gas might explain the ice ages of the distant past. At the turn of the century, Svante Arrhenius calculated that emissions from human industry might someday bring a global warming. Other scientists dismissed his idea as faulty. In 1938, G.S. Callendar argued that the level of carbon dioxide was climbing and raising global temperature, but most scientists found his arguments implausible. It was almost by chance that a few researchers in the 1950s discovered that global warming truly was possible. In the early 1960s, C.D. Keeling measured the level of carbon dioxide in the atmosphere: it was rising fast. Researchers began to take an interest, struggling to understand how the level of carbon dioxide had changed in the past, and how the level was influenced by chemical and biological forces. They found that the gas plays a crucial role in climate change, so that the rising level could gravely affect our future. (This essay covers only developments relating directly to carbon dioxide, with a separate essay for Other Greenhouse Gases. Theories are discussed in the essay on Simple Models of Climate.)</span>
Answer:
True
Explanation:
In pi bonds, the electron density concentrates itself between the atoms of the compound but are present on either side of the line joining the atoms. Electron density is found above and below the plane of the line joining the internuclear axis of the two atoms involved in the bond.
Pi bonds usually occur by sideways overlap of atomic orbitals and this leads to both double and triple bonds.
The formula for mole is
n= Mass/Mol mass
Mol Mass: S=32
O2= 16(2)
—————
64 g/mol
N= 17.50 g
————— (cancel both g)
64 g/mol
= 0.27 mol is the answer
The fire triangle is composed of
1) heat
2) fuel
3) oxidizing agent (oxygen)
Types of fire extinguishers:
1) Water and Foam - <span> extinguish the fire by taking away the </span>heat<span> element of the fire triangle. Foam agents separate the </span>oxygen<span> element from the other elements.</span>
2) Carbon dioxide - <span>extinguish fire by taking away the </span>oxygen<span> element of the fire triangle and also be removing the </span>heat<span> with a very cold discharge.</span>
3) Dry Chemical - <span>extinguish the fire primarily by interrupting the </span>chemical reaction<span> of the fire triangle.</span>
4) Wet Chemical - <span>extinguishes the fire by removing the heat of the fire triangle and prevents re-ignition by creating a barrier between the </span>oxygen<span> and </span>fuel<span> elements</span>
5) Clean Agent - <span>extinguish the fire by interrupting the </span>chemical reaction<span> of the fire triangle</span>
6) Dry Powder - extinguish the fire by separating thefuel<span> from the </span>oxygen<span> element or by removing the </span>heat<span> element of the fire triangle</span>
7) Water Mist - <span>extinguish the fire by taking away the </span>heatelement of the fire triangle
8) Cartridge Operated Dry Chemical - extinguish the fire primarily by interrupting the chemical reaction<span> of the fire triangle</span>
