melting and boiling points

TEKS 5.5B

The student knows that matter has measurable physical properties and those properties determine how matter is classif ied, changed, and used.

The student is expected to:identify the boil ing and freezing/melting points of water on the Celsius scale.

Boiling point is the temperature at which something becomes a gas.

Water has a boil ing point of 100° C.

This means that at 100° C, water changes from a l iquid to a gas.

Melting point is the temperature at which something becomes a liquid.

Water has a melting point of 0° C.This means that at 0° C, water changes from a solid to a l iquid.

Which of the following is the temperature at which ice melts?

A. 0 KelvinB. 0 o FahrenheitC. 0 o CelsiusD. 0 Gram

Which of the following is the temperature at which ice melts?

A. 0 KelvinIncorrect

Kelvin is the measurement unit that includes absolute zero. The temperature would have to be 274 K for ice to melt.

Which of the following is the temperature at which ice melts?

B. 0 o FahrenheitIncorrect

Fahrenheit is the measurement unit that is tradit ional in the U. S. The temperature would have to be 32 o F for ice to melt.

Which of the following is the temperature at which ice melts?

D. 0 GramIncorrect

A Gram (g) is the measurement unit used to represent mass – not temperature.

Which of the following is the temperature at which ice melts?

C. 0 o CelsiusCorrect

The Celsius scale uses 0 o as the melting point .

If you are camping at sea level and want to boil water so it will be safe to drink, what temperature will it need to reach?

A. 15 KB. 100 o CC. 100 o FD. 150 g

If you are camping at sea level and want to boil water so it will be safe to drink, what temperature will it need to reach?

A. 15 KIncorrect

Kelvin is the measurement unit that includes absolute zero. The temperature would have to be 373 o K for water to boil.

If you are camping at sea level and want to boil water so it will be safe to drink, what temperature will it need to reach?

C. 100 o FIncorrect

Fahrenheit is the measurement unit that is tradit ional in the U. S. The temperature would have to be 212 o F for water to boil.

If you are camping at sea level and want to boil water so it will be safe to drink, what temperature will it need to reach?

D. 150 g Incorrect

A gram is the measurement unit for mass – not temperature.

If you are camping at sea level and want to boil water so it will be safe to drink, what temperature will it need to reach?

B. 100 o C Correct

The Celsius scale uses 100 o as the boil ing point for water.

Four students were working together in a lab group. They had to predict the temperature at which pure water would boil. They recorded their predictions in the table below.

StudentPrediction

o C

1 75

2 90

3 100

4 125

Which student’s prediction was the closest to the boiling point of

water?

A. Student 1B. Student 2C. Student 3D. Student 4

StudentPrediction

o C

1 75

2 90

3 100

4 125

Which student’s prediction was the closest to the boiling point of

water?

C. Student 3Correct

100 o C is the boil ing point of water.

Student Predict ion o C

1 752 903 1004 125

Which student’s prediction was the closest to the boiling point of water?

A. Student 1B. Student 2D. Student 4Incorrect

None of these are the boil ing point of water on the Celsius scale.

Student Prediction o C

1 752 903 1004 125

Students were doing a lab to find the melting point of ice. Which thermometer would show the temperature in o Celsius at which ice would begin to melt?

A. Thermometer 1B. Thermometer 2C. Thermometer 3D. Thermometer 4

1 2 3 4

Students were doing a lab to find the melting point of ice. Which thermometer would show the temperature in o Celsius at which ice would begin to melt?

The correct answer is C because ice melts above 0 o C andthe question asks at whattemperature ice would begin tomelt.

1 2 3 4

Students were doing a lab to find the melting point of ice. Which thermometer would show the temperature in o Celsius at which ice would begin to melt?

Answer A is incorrect because water boils at 100°

C.

1 2 3 4

Students were doing a lab to find the melting point of ice. Which thermometer would show the temperature in o Celsius at which ice would begin to melt?

Answer B is incorrectbecause the thermometer reads

50°C.

1 2 3 4

Students were doing a lab to find the melting point of ice. Which thermometer would show the temperature in o Celsius at which ice would begin to melt?

Answer D is incorrectbecause the thermometer reads -5° C.

1 2 3 4