26 questions
How many atoms in all are in a molecule of serotonin?
C10H12N2O
In a ___________change, a substance changes into a different substance.
Physical
Chemical
Which of these is NOT a sign that a chemical change has occurred?
A loss of transparency
An unexpected color change
A temperature change
The formation of a precipitate
The Law of Conservation of Mass states
that matter exists in all states and reacts the same
that matter can only be changed into new substances by introducing a catalyst
that matter exists in the same state throughout any chemical change
that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants
How many Al atoms are in this compound? 4Al2O3
2
8
6
4
How many F atoms are in this compound?
6MgF2
2
6
8
12
a copper penny turning greenish after a few years.
Physical change
Chemical change
An gel ice pack getting cold after you put it in the freezer for an hour.
Chemical change
Physical change
Which of the following IS a physical change?
Getting a haircut
Rusty metal
sour milk
A compound
___________________ are the elements or compounds that leave (are formed in) a chemical reaction.
Polymers
Bonds
Reactants
Products