Two models of the same compound are shown. on the left labeled model a 2 large overlapping black spheres with 3 small blue spheres overlapping the rear black sphere and 2 medium red spheres overlapping the front black sphere. one of the red spheres has a small blue sphere overlapping it. on the right labeled model b 2 c's connected by a black line. the c on the left has 3 h's attached by 1 black line each and the c on the right has 2 os attached to it. the top o is attached by 2 black lines and the bottom o by 1 black line. the bottom o also has an h attached to it by 1 black line. in what way is model a better than model b? model a shows the types of elements in the compound, but model b does not. model a shows the total number of atoms in the molecule, but model b does not. model a shows the three-dimensional shape of the molecule, but model b does not. model a shows the number of atoms of each element in the molecule, but model b does not.

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 belive it is water

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.