A __________________ change results in a new substance.
chemical
In this type of reaction, compounds break apart into smaller pieces.
Decomposition
What group on the periodic table is chemically nonreactive because they are stable.
Noble gases, the group at the end of the periodic table
What is an atom that has a negative or positive charge called?
ion
Atoms tend to form molecules of a compound based on the number of ____ in each atom's outermost shell.
electrons
Out of the 4 reaction types, what would the reaction below be?
Zn + CuCl2 ----> Cu + ZnCl2
single replacement
This is the type of bond that occurs when atoms share electrons.
covalent bonds
An atom that loses electrons will have what kind of charge?
positive
True or False: After atoms combine through a chemical change, they will maintain their original properties.
False
Think of sodium and chlorine (2 things we can't eat) combining to form table salt.
Which chemical equation represents a double replacement reaction?
1. Ca + Cl2 ---> CaCl2
2. Pb(NO3)2 + K2CrO4 ---> PbCrO4 + 2KNO3
3. I2 + NaBr ---> NaI + Br2
4. 2H2 + O2--> 2H2O
2
The bond formed when an atom gains or loses electrons.
ionic bons
A chemical _____ uses chemical symbols and numbers to abbreviate the name of a compound.
formula
What does the chemical formula H2O tells us about this molecule?
1. That it is made up of 2 hydrogens and one oxygen that have been chemically combined.
What reaction type is the opposite of a decomposition reaction?
synthesis
What makes an atom stable?
Having a full set of electrons in the outermost shell. Most atoms on the periodic table are not stable. The noble gases are the only stable atoms.
How are atoms and molecules different?
Atoms are the fundamental, single building blocks of matter, while molecules are 2 or more atoms chemically bonded together.