Chapter 3 Chem 1

How do changes in temperature usually affect density?

Generally, density increases with temperature, as the rise of kinetic energy causes a substance to occupy a larger volume. Not all substances behave this way at all temperatures.

Explain the difference between mass and weight. Provide an example to illustrate the distinction.

Mass is the measure of the amount of matter that an object contains and weight is a force that measures the pull of gravity on a given mass. An example is the moon. Your mass is the same, but your weight is different.

Why is the metric system the preferred system of measurement for science?

The metric system is preferred because it is broken down into smaller measurements. Also the metric system is based on the number 10, so it is easier for us, and scientists, to use.

Weight

a force that measures the pull of gravity on a given mass

Mass

a measure of the amount of matter that an object contains; the SI base unit of mass is the kilogram

Significant Figures

all the digits that can be known precisely in a measurement, plus a last estimated digit

Precision

describes the closeness, or reproducibility, of a set of measurements taken under the same conditions

Accuracy

the closeness of a measurement to the true value of what is being measured

Kelvin Temperature Scale

the temperature scale in which the freezing point of water is 273 K and the boiling point is 373 K; 0 K is absolute zero

Celsius Temperature Scale

the temperature scale on which the freezing point of water is 0 degrees Celsius and the boiling point is 100 degrees Celsius

Absolute Zero

the zero point on the kelvin temperature scale, equivalent to 273.15 degrees Celsius