2o points right now
which of the following statements is true?
a. chemical reactions can neither absorb thermal energy nor release thermal energy.
b. chemical reactions can only release thermal energy.
c. chemical reactions can only absorb thermal energy.
d. chemical reactions can either absorb thermal energy or release thermal energy.

Consider a hydrogen atom in the ground state. what is the energy of its electron? =e= jj now consider an excited‑state hydrogen atom. what is the energy of the electron in the =5n=5 level? =e5= j

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.

Nova: secrets of the sun - video guide worksheet due tomorrowfront side (photo up top)back side (below of the following)1) a mass ejection is a wave of billions of tons of electrically charged particles.2) the sun is so huge, a earths could fit inside of it.3) the surface of the sun seems to vibrate because the sun generates waves4) using geoseismology or helioseismology, we can see the physical process under the sun's surface.5) the thickest layer of plasma in the sun is a region called the zone.6) the thinner plasma in the convection zone makes the move in a more ordered way.7) rising and sinking plasma created a mesmerizing structure called 8) the sdo revealed tornadoes or volcanoes, hundreds of miles high, on the surface of the sun9) sdo allows scientists to see sunlight across a range of 10) the earth's field protects us against threats from the sun.11) the plasma layers beneath the surface act as a which gets denser towards the core. 12) can light up along the paths of the magnetic field, making them visible. 13) the sun's the corona, is made of plasma that reaches over 3 million degrees.14) a sun spot is dark because it is cooler or warmer than its surroundings15) magnetic outbursts are more common during the period called solar