G Unit 2 - Measurements & Calculations

What is a conversion factor?

A ratio derived from equalities used to convert from one unit to another.

What is dimensional analysis?

The process of keeping track of units while converting between different units using conversion factors.

How do you convert 2.4 days to hours?

2.4 days × 24 hr/day = 57.6 hr.

How many inches are in 2.5 miles?

2.5 miles × 1760 yards/mile × 3 ft/yard × 12 in/ft = 158

What is the standard metric unit for mass?

Kilogram (kg).

What is the significance of significant figures?

They indicate the precision of a measurement

What is the doubtful digit in a measurement?

The last digit in a measurement that is estimated.

How do you determine significant figures when a decimal is present?

Count from the left to the right

How do you determine significant figures when a decimal is absent?

Count from the right to the left

What is the rule for adding or subtracting significant figures?

Align the numbers by the decimal point and round to the least number of decimal places.

What is the rule for multiplying or dividing significant figures?

The result should have the same number of significant figures as the measurement with the least significant figures.

What does PEMDAS stand for?

Parentheses

What is scientific notation?

A way to express very large or very small numbers in the form a × 10^n

How do you convert a number to scientific notation?

Move the decimal point to create a coefficient between 1 and 10 and count the number of places moved to determine the exponent.

What is the difference between accuracy and precision?

Accuracy refers to how close a measurement is to the true value

What is qualitative data?

Descriptive data that is non-numerical

What is quantitative data?

Data that is numerical and includes units

How do you express 25.0 g of Lithium (Li) in moles?

25.0 g Li × (1 mol Li / 6.94 g Li) = 3.60 mol Li.

What is the SI unit for volume?

Liter (L).

How do you convert 3.56 kg to mg?

3.56 kg × 1000 g/kg × 1000 mg/g = 3

What is the process to convert 0.052 km to cm?

0.052 km × 1000 m/km × 100 cm/m = 5200 cm.

How do you convert 38129 mL to L?

38129 mL × (1 L / 1000 mL) = 38.129 L.

What is the result of (2.43 × 10^4) × (4.43 × 10^5)?

1.08 × 10^10.

What is the result of 0.0023 × (3 × 10^7) / (4.3 × 10^13)?

1.60465 × 10^-9.

How many significant figures are in the measurement 0.0070?

3 significant figures.

What is the result of 5.12 m × 223 m?

1140 m² (rounded to 3 significant figures).