Answer:
A) they help transport some substances through the membrane.
Explanation:
The membrane proteins that span the bilayer of phospholipids help in the transport of polar, large and charged substances across the membrane. The nonpolar core of the membrane does not allow these charged and polar substances to pass through. Proteins serving as channels form pores to allow movement of the specific substances.
On the other hand, carrier transport proteins of the membrane bind to the substances present at one side of the membrane and deliver them to the opposite side.
N2(g) + 3H2(g) <--> 2NH3(g)
Bear in mind that this is a reversible reaction.
The water cycle is the continuous movement of water all around the Earth. The water cycle is like a big circle and doesn’t really have a starting point. There are 4 main stages involved in water cycle i.e. evaporation, condensation, precipitation and runoff. So, how does this cycle works? When the sun shines, the water from the ocean or lake evaporates due to heat from the sun. When it evaporates, it turns into water vapor and goes up into the atmosphere. This water vapor gets together with other water vapor and turns into a cloud. When clouds get dense, they drop the water back to Earth in some form of precipitation like rain, snow, hail or sleet. When the water falls back down to the Earth, they find their way on the ground surface into puddles, streams and rivers<span>. Again this water will evaporate and the whole cycle will start again.</span>
C) Valence electrons may be lost or gained by an atom when bonding occurs with another atom
