Unit 4- Reactions (Chemistry)

What are physical properties?

something that can be observed without changing the composition of the substance

What is a physical change?

a change to the physical properties

What are chemical properties?

observable characteristics relating to the chemical makeup of a substance

What is a chemical change?

transformation of one or more atoms or molecules into one or more different molecules

What is there a change in when there is a chemical change?

a change in the composition of the substance

What is there a change in when there is a physical change?

a difference in the appearence, size, or display of the substance without a change in composition.

What are reactants?

the starting substances in a reaction

What are products?

the substances produces after reaction takes place

What is synthesis?

two reactants coming together to form one product

What is decomposition?

1 reactant breaking apart to form 2 or more products

What is single replacement?

element replacing another in a compound (1 element ends up single)

What is double replacement?

ions trading partners, a precipitate forms

What is combustion?

a hydrocarbon reacts with O2 to produce CO2 and H2O

Because of the law of conservation of mass, what must be true?

the number of atoms of each element must be equal for the reactants and the products

What is the law of conservation of mass?

chemical reactions must be balacenced, aka the # of atoms on the reactant side and the product side must be equal

How do you decide if an equation is balanced?

compare the numbers of atoms of each element that appear on each side of the equation

How do you predict products?

single replacement, when one element replaces another element