Chemical reactions

The definition: Two or more atoms bonded together, representing the smallest unit of a chemical compound that can take part in a chemical reaction, best matches

• molecule
• atom
• mixture
• element

N_2, Cl_{2, and} O₂ are all 

• diatomic molecules.
• ionic bonds.
• of equal mass.
• solids.

Identify the Reactants in this equation.

• A

• B

What state of matter is this substance?

• solid

• liquid

• gas

• aqueous

A chemical reaction is balanced when

• both sides have the same elements
• Both sides have the same  number of atoms
• Same subscripts
• Same coefficients

In a synthesis reaction

• A compound breaks apart into two or more compounds
• Two or more compounds make one single product
• CO₂ and H₂O must be products
• O₂ must be a reactant

C₄H₆  + 3O₂ ---------> 4CO₂  +  3H₂O is a 

• Decomposicion reaction
• Combustion reaction
• Sintesis reaction
• None of the above

Which of the following describes the law of conservation of mass?

• In a reaction, atoms are created or destroyed.
• In a reaction, atoms are not lost or made.
• In a reaction, the mass of the product may be more or less than the reactants.
• In a reaction, mass never stays the same.

Describes the number of molecules in a compound and is used to balance a chemical reaction. 

• coefficient 
• subscript
• superscript
• SI unit

2 NaBr + 1 Ca(OH)₂ ----> 1 CaBr₂ + 2 NaOH

• Synthesis (or combination)
• Decomposition
• Single displacement
• Double displacement