Scientific Notation
Expressing numbers as a coefficient between 1 and 10 times a power of ten.
Practise Analytical, Lab & Spectroscopy All Analytical, Lab & Spectroscopy topics
Expressing numbers as a coefficient between 1 and 10 times a power of ten.
Practise Analytical, Lab & Spectroscopy All Analytical, Lab & Spectroscopy topics
Scientific notation writes a number as a coefficient a between 1 and 10 multiplied by a power of ten, N = a x 10^n. This format expresses very large or small quantities such as Avogadro's constant or atomic masses compactly and avoids long strings of zeros. When numbers are multiplied, their coefficients are multiplied and the exponents are added, and when divided the exponents are subtracted, which makes order-of-magnitude estimates quick. The number of digits in the coefficient also shows the number of significant figures, so 3.00 x 10^8 clearly has three significant figures while 300000000 does not. Calculators display the same idea in E notation. Mastering this notation is essential before doing stoichiometry or concentration calculations.
Key ideas: Move the decimal until the coefficient lies between 1 and 10, counting moves as the exponent: positive for large numbers, negative for numbers below 1. To add or subtract, first match exponents. When raising to a power, multiply exponents: (2 x 10^3)^2 = 4 x 10^6. Enter values on a calculator with the EXP key, not by typing x 10 and a power.
Common mistakes and connections: A frequent error is typing 6.02 x 10^23 as 6.02*10^23 on a calculator without brackets in a quotient, which gives a wrong result, or keeping the exponent unchanged after adding numbers. Students also forget that 0.00045 is 4.5 x 10^-4, not 4.5 x 10^-3. Negative exponents mean small numbers, not negative numbers. Supports mole and concentration calculations and significant figures.
Physical constants span more than forty powers of ten, so they are written as a coefficient times a power of ten and placed on a logarithmic axis. The interactive lesson shows this as a live animation or chart.
Avogadro's constant is 6.022 x 10^23 mol-1, and the elementary charge is 1.602 x 10^-19 C.
Expressing numbers as a coefficient between 1 and 10 times a power of ten.
Scientific Notation is a beginner topic in Analytical, Lab & Spectroscopy. It needs no earlier chemistry lessons and is a good starting point.
Study these earlier topics in Analytical, Lab & Spectroscopy first: Measurement and Units, Significant Figures, Accuracy and Precision.
The next topics in Analytical, Lab & Spectroscopy are Dimensional Analysis and Density.
Yes. The interactive lesson includes a self-check question on Scientific Notation, and the Analytical, Lab & Spectroscopy quiz draws on every topic in this area.
Scientific Notation is topic 7 of 99 in Analytical, Lab & Spectroscopy.