Data: a h f values: ch 4( g), -74.8 kj; co 21 g), -393.5 kj; h 20( 1), -285.8 kj. using the a h f data above, calculate a h xn for the reaction below. reaction: ch 4( 9) + 20 2( 9) => co 2(g) + 2h 2011) selected d. -890.3 kj correct d. -890.3 kj

Water is initially present in a state where its molecules are far apart. during a change of state, its molecules slow down. which change of state has most likely taken place? from a gas to a liquid from a liquid to a gas from a solid to a liquid from a gas to a plasma

What will most likely happen in the absence of a cell membrane? a) photosynthesis will not take place. b) the cell will not store food, water, nutrients, and waste. c) energy will not be released during cellular respiration. d) substances will pass in and out of the cell in an uncontrolled manner.

Scientists have developed an explanation of a phenomenon from several verified hypotheses. the explanation has been confirmed through numerous experimental tests.which option best describes this explanation? a. scientific lawb. research questionc. hypothesisd. scientific theory