Pre-IB Chemistry

Test 1

Significant Digits

• Significant Digits: the actual digits that are being measured by an instrument.

• Precision is determined by one place value greater precision than the smallest marking on the instrument.

Rules for determining

1. All nonzero digits are significant

2. If the last digits is 0 and preceded by a decimal, it’s significant

3. All zeros between significant digits are significant

Examples

468cm - 3 significant figures

79.0g - 3 significant figures

13000g - 3 significant figures

40700.0N - 6 significant figures

0.00608N - 3 significant figures

Dimensional Analysis

Metric Base Units

Time: second

Mass: grams (kg is SI)

Length: meter

Volume: liter

Temperature: Kelvin