"Density" Quality and Density PPT

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"Density" Quality and Density PPT

Part One: Preview Perception

1. The relationship between mass and volume of matter

1. For the same substance, the ratio of mass to volume is ________.

2. The ratio of mass to volume of different substances is generally ________.

3.The mass and volume of the same substance form ________.

2. Density

1. Concept: The ratio of the ________ of an object composed of a certain substance to its ________.

2.Formula:____________________.

3. Unit.

(1) International unit: ________.

(2) Commonly used units: ________.

(3)Conversion relationship: 1 g/cm3=________kg/m3.

4.The density of pure water: ______________.

Density PPT, Part 2: Interactive Classroom Understanding

Correctly understand the concept of density

Density is a characteristic of matter. The density of the same substance is the same. It does not change with changes in mass and volume. Therefore, density cannot be considered to be directly proportional to mass and inversely proportional to volume. The density of the same substance is affected by temperature (thermal expansion and contraction) and state. Different substances generally have different densities.

For objects composed of the same material, the mass is proportional to the volume, that is, when ρ is constant, _________. No matter how the mass and volume change, their ratio - mass per unit volume - remains unchanged.

[Example] Regarding density, which of the following statements is correct ()

A. Density is directly proportional to the mass of the object and inversely proportional to the volume of the object

B. Density is a characteristic of matter and has nothing to do with the mass and volume of the object.

C. Density has nothing to do with the state of the object

D. Density has nothing to do with the temperature of the object

Tips: Some students may conclude based on the density formula ρ=___ that density is directly proportional to mass and inversely proportional to volume. They think that as the mass of an object increases, the density increases. This idea is wrong. As the mass of an object composed of the same material increases, the volume increases accordingly. However, the ratio of mass to volume remains unchanged, and the density of the material does not change either.

Under the same external environment or conditions, the densities of different substances are generally different, and the densities of the same substance are generally the same. It has nothing to do with the size of the mass or volume, so we say that density is a type of substance itself. characteristic. But when the external environment or conditions change, even for the same substance, its density will change accordingly. The density of a substance is related to its state and factors such as temperature and pressure of the environment.

Analysis: Density is a characteristic of matter. When the temperature and state remain unchanged, the density of a certain substance is certain and does not change with the mass and volume of the object. Therefore, option A is incorrect and option B is correct; when the object is in When the state changes, the density also changes. For example, the densities of water and ice are different, so option C is incorrect; because when the temperature changes, the mass of the object does not change, but the volume of the object changes, so the density of the object will change, so option D is incorrect.

Answer:B

Density PPT, Part 3: Try the application

1. Explore the relationship between mass and volume of matter

1. In order to explore certain characteristics of matter, a student filled in the four sets of measured data in the table below. Please analyze and compare based on the content and data recorded in the table:

(1) Complete the blank spaces in the table.

(2) The similarities between iron and aluminum are: ____________________; the differences are: ____________________.

(3)The density of iron is ____________________ and the density of aluminum is ____________________.

2. Density

2. (2018 Hubei Yichang High School Entrance Examination) Among the following situations, the density of matter remains unchanged ()

A.Tear the paper into pieces

B. Ice melts into water

C. Part of the oxygen in the oxygen tank is used

D. Heat the wire red

3. The density of iron is 7.9×103 kg/m3, its meaning is ()

A.The mass of 1 m3 iron is 7.9×103 kg/m3

B.The mass of 1 m3 iron is 7.9×103 kg

C. The volume of iron with a mass of 1 kg is 7.9×103 m3

D. The substance with a volume of 1 m3 and a mass of 7.9×103 kg/m3 must be iron.

4. A container contains alcohol with a volume of 5×10-3 m3 and a mass of 4 kg. The density of alcohol is ______kg/m3. After half of it is used, the density of the remaining alcohol is ______kg/m3.

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For more information about the "Mass and Density" PPT courseware, please click the "Mass and Density ppt Density ppt" tab.

"Density" Quality and Density PPT download:

"Density" Mass and Density PPT Download Part 1 Contents: Knowledge Points Basic Knowledge Point 1 The relationship between the mass and volume of the same substance 1. In order to study a certain characteristic of a substance, a student used water and alcohol to conduct experimental investigations, and the measured results are as follows Data: (1) In the figure..

"Quality" Quality and Density PPT courseware download:

"Quality" Quality and Density PPT courseware download Part 1: Classification practice of knowledge points Knowledge point 1 Quality 1. The amount of _____ contained in an object is called mass, represented by the symbol ____. The international unit of mass is _____, represented by the symbol ____. quality..

"Quality" Quality and Density PPT teaching courseware:

"Quality" Mass and Density PPT Teaching Courseware Part One: New Knowledge Summary 1. Mass of an object The ______ of the matter contained in an object is called mass. Mass is a basic attribute of an object. It does not change with the object's ______, ______, ______ and temperature..

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Update Time: 2024-10-03

This template belongs to Physics courseware People's Education Edition Physics for Grade 8, Volume 1 industry PPT template

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