Energy, Heat, Temperature, Mass and Density
Watch This!
Misconceptions About Temperature by Veritasium [3:59]
and
Misconceptions About Heat by Veritasium [5:10]
Misconceptions About Temperature by Veritasium [3:59]
and
Misconceptions About Heat by Veritasium [5:10]
Energy is the capacity to do work (applying a force to move matter). Kinetic energy (KE) is the energy of motion;
potential energy is energy due to relative position, composition, or condition. When energy is converted from
one form into another, energy is neither created nor destroyed (law of conservation of energy or first law of
thermodynamics).
Matter has thermal energy due to the KE of its molecules and temperature that corresponds to the average KE of its
molecules. Heat is energy that is transferred between objects at different temperatures; it flows from a high to a low
temperature. Chemical and physical processes can absorb heat (endothermic) or release heat (exothermic). The SI
unit of energy, heat, and work is the joule (J).
Source: Chemistry by openstax
The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. Generally, in chemistry we measure density in units of g/mL (for solids and liquids) or g/L (for gases).
For a pure substance the density has the same numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium and iridium are the densest known elements at standard conditions for temperature and pressure but certain chemical compounds may be denser.
To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity "relative density" or "specific gravity", i.e. the ratio of the density of the material to that of a standard material, usually water. Thus a relative density less than one means that the substance floats in water.
The density of a material varies with temperature and pressure. This variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object and thus increases its density. Increasing the temperature of a substance (with a few exceptions) decreases its density by increasing its volume.
Source: Density on Wikipedia accessed 24 Jan 2017.
Introductory Level Videos
Temperature Conversions by TheChemistrySolution [2:37]
This chemistry tutorial covers how to convert temperatures beween units of degrees Fahrenheit, degrees Celsius and Kelvin, and includes the formulas necessary for these conversions as well as examples of how to calculate these conversions.
Density Calculations by TheChemistrySolution [3:24]
This video tutorial covers density and how to calculate density, mass or volume given the other two values.
Calculate Kelvin; Celsius to Kelvin; Kelvin to Celsius by ChemistNATE [3:34]
How to convert temperature in Celsius to temperature in Kelvin (add 273.15)
How to convert temperature in Kelvin to temperature in Celsius (subtract 273.15)
Chemistry 7.1 Temperature and Energy by IsaacsTEACH [9:37]
This lesson discusses what temperature is and how it relates to Kinetic Energy. We also look at Kinetic Energy in greater detail as well as Maxwell-Boltzmann distributions of molecular speeds.
Chemistry 10.1 Heat and Energy by IsaacsTEACH [3:25]
What is heat? This lesson discusses heat as the transfer of energy from a hotter area to a cooler area. We also look at how heat is measured, and the difference between calories and Food Calories.
Chemistry 1.6 Density by IsaacsTEACH [3:25]
A discussion of Density as a physical, intensive property of matter, as well as how to calculate it. Water displacement is shown as a technique for determining volume to assist in a density calculation. The effect of temperature on the density of objects is also discussed.
The Difference Between Mass and Weight by Veritasium [3:14]
There is a common perception that weight and mass are basically the same thing. This video aims to tease out the difference between mass and weight by asking people what makes a car difficult to push. The standard answer is that it is difficult to push because it's heavy. But heaviness is a measure of weight, the gravitational pull of the Earth attracting the car to Earth's center. When the car is pushed on a flat road, the force of gravity does not oppose the motion. Instead the resistance felt is an indication of the car's mass which determines its inertia. Inertia is the property of matter that means it tends to resist acceleration - the greater the mass, the less the acceleration for a given amount of force.
Celsius Didn't Invent Celsius by Veritasium [8:11]
Celsius never devised nor used the scale that now bears his name.
What the Fahrenheit?! by Veritasium [5:23]
The crazy story of the arbitrary temperature scale used in a tiny minority of countries.
potential energy is energy due to relative position, composition, or condition. When energy is converted from
one form into another, energy is neither created nor destroyed (law of conservation of energy or first law of
thermodynamics).
Matter has thermal energy due to the KE of its molecules and temperature that corresponds to the average KE of its
molecules. Heat is energy that is transferred between objects at different temperatures; it flows from a high to a low
temperature. Chemical and physical processes can absorb heat (endothermic) or release heat (exothermic). The SI
unit of energy, heat, and work is the joule (J).
Source: Chemistry by openstax
The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. Generally, in chemistry we measure density in units of g/mL (for solids and liquids) or g/L (for gases).
For a pure substance the density has the same numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium and iridium are the densest known elements at standard conditions for temperature and pressure but certain chemical compounds may be denser.
To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity "relative density" or "specific gravity", i.e. the ratio of the density of the material to that of a standard material, usually water. Thus a relative density less than one means that the substance floats in water.
The density of a material varies with temperature and pressure. This variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object and thus increases its density. Increasing the temperature of a substance (with a few exceptions) decreases its density by increasing its volume.
Source: Density on Wikipedia accessed 24 Jan 2017.
Introductory Level Videos
Temperature Conversions by TheChemistrySolution [2:37]
This chemistry tutorial covers how to convert temperatures beween units of degrees Fahrenheit, degrees Celsius and Kelvin, and includes the formulas necessary for these conversions as well as examples of how to calculate these conversions.
Density Calculations by TheChemistrySolution [3:24]
This video tutorial covers density and how to calculate density, mass or volume given the other two values.
Calculate Kelvin; Celsius to Kelvin; Kelvin to Celsius by ChemistNATE [3:34]
How to convert temperature in Celsius to temperature in Kelvin (add 273.15)
How to convert temperature in Kelvin to temperature in Celsius (subtract 273.15)
Chemistry 7.1 Temperature and Energy by IsaacsTEACH [9:37]
This lesson discusses what temperature is and how it relates to Kinetic Energy. We also look at Kinetic Energy in greater detail as well as Maxwell-Boltzmann distributions of molecular speeds.
Chemistry 10.1 Heat and Energy by IsaacsTEACH [3:25]
What is heat? This lesson discusses heat as the transfer of energy from a hotter area to a cooler area. We also look at how heat is measured, and the difference between calories and Food Calories.
Chemistry 1.6 Density by IsaacsTEACH [3:25]
A discussion of Density as a physical, intensive property of matter, as well as how to calculate it. Water displacement is shown as a technique for determining volume to assist in a density calculation. The effect of temperature on the density of objects is also discussed.
The Difference Between Mass and Weight by Veritasium [3:14]
There is a common perception that weight and mass are basically the same thing. This video aims to tease out the difference between mass and weight by asking people what makes a car difficult to push. The standard answer is that it is difficult to push because it's heavy. But heaviness is a measure of weight, the gravitational pull of the Earth attracting the car to Earth's center. When the car is pushed on a flat road, the force of gravity does not oppose the motion. Instead the resistance felt is an indication of the car's mass which determines its inertia. Inertia is the property of matter that means it tends to resist acceleration - the greater the mass, the less the acceleration for a given amount of force.
Celsius Didn't Invent Celsius by Veritasium [8:11]
Celsius never devised nor used the scale that now bears his name.
What the Fahrenheit?! by Veritasium [5:23]
The crazy story of the arbitrary temperature scale used in a tiny minority of countries.