Lesson 1 Flashcards
A description of a reaction using element symbols and chemical formulas
Chemical equation
The starting substances in a chemical reaction
Reactants
The substances produced by the chemical reaction
Products
This law states that the total mass of the reactants before a chemical reaction is the same as the total mass of the products after the chemical reactions
Law of conservation of mass
A number placed in front of an element symbol or chemical formula and an equation
Coefficient
What does it mean for an equation to be balanced
That the number of Adams on each element is the same or balanced on each side of the arrow
What is a sign of a chemical reaction
Chemical properties change
Explain why subscripts cannot change when balancing a chemical equation
Because by changing subscripts you were changing the identities of the substances that are in the reaction
A process in which Adams of one or more substances rearrange to form one or more new substances
Chemical reactions
What are substances made of?
Elements or compounds
What are elements made of?
Atoms
What is the difference between physical changes and chemical changes?
Physical changes produce NO new substances and chemical changes produce new substances.
Signs of a chemical reaction
Properties?
Color
Odor
Formation of Bubbles
Formation of a Precipitate (powder)
Signs of a chemical reaction
Energy
Warming or cooling
Light released
When there is a change in color or a formation of bubbles does it always mean chemical change?
No.
