Perform each of the following calculations, and give an answer with the correct number of significant figures:b. 0.002 78 x 5

Significant figures are the digits in a number that contribute to its precision. This includes all non-zero digits, any zeros between significant digits, and trailing zeros in the decimal portion. Understanding significant figures is crucial for accurately reporting measurements and calculations in chemistry, as it reflects the precision of the data.

When multiplying numbers, the result should be reported with the same number of significant figures as the factor with the least significant figures. This rule ensures that the precision of the result is not overstated. For example, in the calculation of 0.00278 x 5, the number 0.00278 has three significant figures, while 5 has one significant figure, so the final answer should be expressed with one significant figure.

Scientific notation is a way of expressing numbers that are too large or too small to be conveniently written in decimal form. It is represented as a product of a number between 1 and 10 and a power of ten. This notation is particularly useful in chemistry for simplifying calculations and clearly indicating significant figures, especially when dealing with very small or very large quantities.