Agraph is drawn with output on the vertical axis and input on the horizontal axis. what does a straight or “flat” segment indicate on the graph?

When a graph is drawn with output on the vertical axis and input on the horizontal axis, this indicates that the straight or "flat" segment on the graph is the representation of a region where the output doesn't change in response to the input.

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.