Chapter 3 - Matter and Energy
Matter is anything with weight and space.
Matter shall be classed as a mixture or pure substance.
Fixed compositions have pure substances or compounds and variable compounds have mixtures.
The substances can be separated by physical methods in mixtures.
Solid, liquid, and gas are the three states of matter.
A physical feature is a feature of a substance because it can be observed or measured without affecting its identity.
When physical properties change, the composition of the substance does not change. Physical changes happen.
A chemical property shows a substance's ability to switch to another.
When a substance with new physical and chemical properties is formed, a chemical change takes place.
The temperature in science is measured in Celsius (°C) or kelvins (K).
On the Celsius scale, the point of freeze (0 °C) and the point of boiling (100 °C) are 100-unit water.
There are 180 units in scale Fahrenheit between the frostbite (32 °F) and the hotbed (212 °F) of the water.
The temperature of Fahrenheit by the equation TF = 1.8(TC) + 32 is related to the Celsius temperature.
The SI unit, kelvin, is associated by equation TK = TC + 273 with the Celsius temperature.
The ability to work is energy.
Potential energy is energy stored; kinetic energy is moving energy.
Calorie (cal), kilocalorie (kcal), joule (J), and kilojoule are common energy units (kJ).
One calorie is 4.184 J.
The calorie in nutrition is equal to 1 kcal or 1000 calories of energy.
The energy of a food is the sum of carbohydrates, fat, and protein kilocalories or kilojoules.
Specific heat is the amount of power needed to exactly 1 g of a substance to increase its temperature by 1 °C.
Through the multiplication of the mass, temperature change, and specific warmth the heat is lost or recovered by a substance.
A fusion occurs when the solid particles absorb sufficient energy to break down and form a liquid.
Fusion thermal means the amount of energy necessary to precisely convert 1 g of solid into liquid.
For water, it is necessary to melt 1 g of ice or to freeze 1 g of water, cal (334 J).
Evaporation occurs when particles absorb sufficient energy in a fluid state to separate and form gas particles.
Boiling at the boiling point is the vaporization of the liquid.
The amount of heat required to convert 1 g of fluid to vapor is the heat of the vaporization.
Sublimation is a process through which solid changes into a gas directly.
A heating or cooling curve shows temperature and condition changes when heat is added to or removed from a material.
Changes to the state are shown in plateaus on the graph.
The sum of the energy calculations for state change and/or temperature change(s) is the total heat absorbed or removed from a substance undergoing changes in temperature and state.