The trapping of heat in the lower atmosphere (the troposphere), referred to as the greenhouse effect, is a natural process that helps regulate the temperature of our planet, allowing for life on Earth to exist and flourish. Nitrogen and oxygen molecules make up 99% of Earth's atmosphere, with water and carbon dioxide accounting for less than 0.5%. This natural greenhouse effect is the result of heat absorption by H2O and CO2 molecules in the lower atmosphere, and re-radiation of this trapped heat back to Earth's surface. Without the natural greenhouse effect, Earth's temperature would be 0°F instead of its present 57°F. The question for some is whether human activities are causing an increase of the greenhouse effect, and thus global climate change. Scientific data collected in the past fifty years indicates that the concentration of greenhouse gases in the atmosphere has been increasing and the greenhouse gas that has stabilized in the lower atmosphere is
CFC.

Which greenhouse gas is most abundant naturally?

a. Trace gases

b. Water vapor

c. Carbon dioxide

d. Methane

e. Nitrous oxide

Check the correct box to describe the periodic trends in electronegativity. electronegativity across a period: decreases. increases. electronegativity down a group: decreases. increases.

Lem 2 the data below are for the system ethyl propyl ether (1)-chloroform (2) at 0.5 bar. use the data to answer the following questions (all questions refer to p d 0: 5 bar). a) what are the boiling points of the pure components at 0.5 bar? b) a mixture with the overall composition z1 d 0: 1 is brought to 47.6ä±c, 0.5 bar. what is the phase? c) 100 mole of a mixture with z1 d 0: 1 (state a) is mixed with 22 mole of pure ethyl propyl ether vapor (state b). the mixing takes place at 47.6 ä±c, 0.5. bar. what is the phase of the resulting mixture (state c)? if the state is a v/l mixture report the number of moles and mole fractions in each phase. d) plot the txy graph and show states a, b and c. the graph must be done by computer and should be properly annotated. ethyl propyl ether (1) - chloroform (2) at 0.5 bar t ( ä±c) x1 y1 t ( ä±c) x1 y1 42.9 0.000 0.000 49.0 0.470 0.455 43.0 0.020 0.010 49.1 0.520 0.520 43.9 0.065 0.029 48.9 0.567 0.592 45.4 0.156 0.089 48.3 0.652 0.720 46.4 0.215 0.142 47.6 0.745 0.815 47.6 0.296 0.223 46.7 0.822 0.872 48.3 0.362 0.302 45.7 0.907 0.937 48.7 0.410 0.375 44.6 1.000

What state of matter is ice a. liquid b. element c. solid d. gas