UNIT 4- ENERGY AND CHANGES Flashcards
Energy comes in…
Many forms of
Energy can be…..into another form of energy
Transformed
What is energy?
The ability to do work or effect change
What is the unit of measurement for energy?
Joule (J)
What is energy transfer?
The movement of energy from one place to another
What is energy transformation?
The changing of energy from one form to another
What is the law of conservation of energy?
Energy can neither be created or destroyed.
What do thermal energy results from?
The particles random movement
What are the two factors thermal energy depend on?
• temperature
• number of particles
What is the transfer of thermal energy between two environment called?
Heat
Heat always passes from the…. Environment to the…… environment
Warmer, cooler
Temperature only takes what into account?
Speed particles
What do heat depends on?
The speed
What do particles depend on?
Mass
What do heat expressed in?
Joules (J)
What are the three type of changes in matter?
Physical, chemical and nuclear changes
When do physical change occur?
When the form or state of a substance is changed.
In physical changed the…
Characteristic properties and molecules stayed the same
What do the chemical change alters?
The nature of the substance and the molecules
Which transformation involves REARRANGING the bonds between atoms and forming molecules?
Chemical change
How can we recognize a chemical change has taken place?
• Release of gas
• emissions or absorption of heat
• a change in colour
• the formation of a precipitate
How can a chemical change or reaction be represented?
By a chemical Equation
In a chemical equation… substances are represented by…
Chemical symbols and formulas
What is the law of conservation of mass?
In a chemical change the mass of the reactants is equal to the mass of the products
What is Neutralization?
A chemical change in which an acid and base react together to form a salt and water
What is combustion
A chemical reaction in which substances combine with oxygen, it always releases energy
What are the 3 types of combustion?
• Slow combustion
• Spontaneous combustion
• Rapid combustion
Examples of SLOW COMBUSTION
Cut apples turning brown, iron rusting, cellular respiration etc.
What is Spontaneous combustion?
Form of combustion in which substances starts burning on their own
What is Rapid combustion?
A type of combustion in which substances burn with a flame.
How can we recognize combustion?
Heat and light are always produced
What is the triangle of fire?
Sets the conditions that must be fulfilled for rapid combustion to take place
What is photosynthesis?
A chemical reaction taking place in plants. Plant cells use solar energy to produce Glucose and oxygen from carbon dioxide and water
What is Cellular respiration?
A chemical change that uses Glucose and Oxygen to form carbon dioxide and water
Where do cellular respiration takes place in?
Every cell of a living animal
