SHORT ANSWER

Show how to convert the temperature 84.7° C to Kelvin.

84.7 + 273 = 357.7 K

Explain how hypothesis and theory are different.

A hypothesis is a prediction of the outcome of one experiment. A theory is a description of how a process is believed to occur

A student records the temperature of a mixture of ice and rubbing alcohol as -3.8 K. Is this a valid measurement? Explain your answer.

it is impossible for a particle to have less than zero energy, negative Kelvin temperatures are meaningless and cannot be recorded.

Define an independent variable in an experiment. Explain the term with respect to the solubility of salt at different temperatures.

plan to change in an experiment. checking the solubility of salt at different temperatures, you need to conduct experiments at different temperatures., temperature is the independent variable in the experiment. Solubility is the dependent variable.

What two things does a conversion factor do?

1. cancels one unit 2. introduces a new unit

A crystalline compound such as sodium chloride has very high melting point. Which of the following macroscopic properties can be explained in submicroscopic level? 1. Structure 2. Composition 3. Behavior

All

Infer a qualitative measurement that can be made from the scene shown.

Answers should be descriptions of object without using numbers (counting or measuring).

Infer a quantitative measurement that can be made from the scene shown.

Answers should include a numerical value obtained from measurement or counting.

Explain how a thermometer can measure changes in temperature.

As the temperature changes, the volume of the liquid changes. This causes the height of the liquid in a long glass tube to vary. Markings on the glass tube allow changes in temperature to be recorded.

Compare and contrast pure research and applied research.

Both are ways of doing science. Pure research is conducted for the purpose of discovering new knowledge, while applied research is conducted to solve a specific problem.

Explain the difference between experimental error and percent error.

Experimental error is the amount that a measured value is different from the accepted value, found by subtracting the values. Percent error is the experimental error relative to the accepted value.

What must be immediately done if chemicals come in contact with the eyes or skin while performing an experiment in the laboratory

Flush the area immediately with large quantities of water and inform the teacher of the spill and the chemical.

Explain the difference between mass and weight.

Mass is a measurement of the amount of matter in a substance, while weight is a measure of gravity's effect on that mass.

Explain why mass is used instead of weight in scientific studies.

Mass is measured independently of gravitational force and remains constant no matter where it is measured. Weight can change depending on an object's location since gravity's effect might be different in another location.

History of rockets can be traced back to the firecrackers in eastern countries for ages. Rockets are now advanced enough to go beyond the solar system. Which kind of research has made this possible?

Practical use of scientific information of pure and applied research can be named technology. So, research and advancements in rockets is technology.

Discovery of the effect of CFCs on environment was accidental and generated a lot of interest and research in this field. Which category of research is classified by further studies?

Research undertaken to solve a specific problem is called applied research. Further research on the depletion of ozone layer due to CFCs, after the initial discovery, is applied research.

The data for two different measurements are shown below. Which experiment was more accurate? Explain your answer. Sample Measured value Accepted Distance 54,700 m 57,900 m Mass 61.3 g 65.7 g

The distance measurement has an error of 5.53%. The mass measurement has an error of 6.70%. Therefore, distance was measured more accurately.

How is ozone formed from the oxygen gas in the stratosphere?

The energy of ultraviolet radiations breaks the oxygen gas into oxygen atoms, which then interact with the oxygen gas to form ozone.

Evaluate this dimensional analysis setup. A paperclip is 3.2 cm long. How many paperclips would fit in a football field (100 yards) if 1 inch = 2.54 cm?

The second conversion factor, 1 inch = 2.54 cm, is reversed. It needs to be arranged so that the unit in the denominator of one fraction can cancel out the unit in the numerator of the next fraction, and so on.