The graph shows the changes in the phase of ice when it is heated.

which of the following temperatures describes the value of b?

a) 0 °c, because it is the melting point of ice.

b) 100 °c, because it is the boiling point of water.

c) greater than 0 °c, because a represents the temperature at which ice melts

d) greater than 100 °c, because a represents the temperature at which water evaporates.

Option (A) is the correct answer.

Explanation:

A temperature at which both solid and liquid state of water are present in equilibrium is known as melting point and the temperature remains constant during this transition of phase.

As it is shown in the graph that temperature at point A is zero degree celsius that is, the temperature at which water freezes completely. And, point B shows that solid and liquid phase are in  equilibrium. This means that the temperature at point B is also zero degree celsius.

Hence, we can conclude that temperature at point B is , because it is the melting point of ice.  

explanation:

the largest database of organic compounds lists about 10 million substances, which include compounds originating from living organisms and those synthesized by chemists. the number of potential organic compounds has been estimated at 1060—an astronomically high number. the existence of so many organic molecules is a consequence of the ability of carbon atoms to form up to four strong bonds to other carbon atoms, resulting in chains and rings of many different sizes, shapes, and complexities. the simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons. even though they are composed of only two types of atoms, there is a wide variety of hydrocarbons because they may consist of varying lengths of chains, branched chains, and rings of carbon atoms, or combinations of these structures. in addition, hydrocarbons may differ in the types of carbon-carbon bonds present in their molecules. many hydrocarbons are found in plants, animals, and their fossils; other hydrocarbons have been prepared in the laboratory. we use hydrocarbons every day, mainly as fuels, such as natural gas, acetylene, propane, butane, and the principal components of gasoline, diesel fuel, and heating oil. the familiar plastics polyethylene, polypropylene, and polystyrene are also hydrocarbons. we can distinguish several types of hydrocarbons by differences in the bonding between carbon atoms. this leads to differences in geometries and in the hybridization of the carbon orbitals.

i think   the answer is c hope i'm right