chemistry part one Flashcards
What is a chemical reaction?
A process in which one or more substances (known as reactants), converted into products during the process.
What is the difference between a physical and chemical change?
Physical changes affect a substance’s appearance, no its chemical content. Chemical changes lead a substance to convert into a completely different substance with a new chemical formula.
Identify 3 signs of physical change
Expected color change, change in size or shape, change in state of matter, no new substance formed.
Identify 3 signs of chemical change.
Color change, change of temperature, evolution of a gas (formation of bubbles), precipitate (formation of a solid).
What does the arrow indicate in a chemical equation?
It is used to describe the state or progress of a reaction.
What is the Law of Conservation of Mass?
The law of conservation of mass states that in a chemical reaction mass is neither created nor destroyed.
What is a spontaneous reaction?
A chemical reaction that doesn’t need an activation energy input.
What is a non-spontaneous reaction?
A chemical reaction that requires activation energy.
What is an exothermic reaction?
Is when energy is released during a chemical reaction in the form of heat, light, and sound.
What is an endothermic reaction?
Is when energy is absorbed during a chemical reaction in the form of heat and light.
Identify 3 endothermic reactions.
Melting ice cubes, evaporating water, melting solid salts.
Identify 3 exothermic reactions.
Lighting a sparkler, fireworks, lighting a stove.
What does combustion mean?
Combustion is the scientific name for burning.
What is needed to start a combustion reaction?
Oxygen from the air.
What is photosynthesis?
Photosynthesis is the conversion of light energy into chemical energy by green plants and other organisms.
What are the reaction conditions for photosynthesis?
Oxygen, water, sunlight.
What is cellular respiration?
cellular respiration is a sequence of metabolic activities that occur within a cell
