Final answer:
To describe an object 100 times greater than a grain of sand in scientific notation, we assume the size of a grain of sand as 1 x 10¹¹ millimeters, thus the object would be 1 x 10² millimeters or alternatively 1.0 x 10¹ centimeters.
Step-by-step explanation:
An object is said to be 100 times greater than the size of a grain of sand. To describe the size of this object in scientific notation, we first need a reference size for a grain of sand. Let's assume an average grain of sand is about 1 millimeter in diameter, which can be written as 1 x 100 millimeters because it is a unit measurement without needing to alter the scale.
Now, if an object is 100 times greater, it is 100 times 1 millimeter, which equals 100 millimeters or 1 centimeter. In scientific notation, this is written as 1 x 102 millimeters. But since scientific notation requires a digit term between 1 and 10, and an exponential term as a power of 10, we can also write this as 1.0 x 101 centimeters, which is the preferred way to express numbers in this form.
To summarize, 1 millimeter is equivalent to 1 x 100 millimeters in scientific notation, and 100 millimeters is equivalent to 1 x 102 millimeters or 1.0 x 101 centimeters when expressed in scientific notation.