The most basic building block of matter (smallest part of an element) is called a(n) __________. 

• Product
• Reactant
• Atom
• Molecule

A(n) _____ is a unique substance that forms when two or more elements combine chemically.

• element
• compound
• mixture
• all of the above

A compound always has the same ___________ in the same proportions (ratio).

• elements
• carbons
• mixtures
• ions

A(n) _____ is the smallest particle of a compound that still has the compound’s properties.

• atom
• molecule
• element
• mixture

A physical property can be observed by _________________.

• burning the substance
• changing the chemical identity of a substance
• using the senses
• placing the substance in acid

Signs that a chemical change has occurred include

• a change in color
• the release of bubbles
• the production of an odor
• all of the above

All the elements on the left side of the periodic table are called..

• Metals

• Metalloid

• Nonmetals

The positive particles of an atom are 

• electrons 
• positrons 
• neutrons 
• protons 

A substance that is made up for one type of atom is called an:

• atom
• element
• compound
• mixture

Which of these elements is a metal?

• argon
• carbon
• iron
• hydrogen