Chemistry and Matter

Which of these determines the identity of an atom?

• Number of electrons
• Number of protons
• Number of energy levels
• Number of neutrons

The nucleus of an atom contains

• only neutrons
• protons and electrons
• protons and neutrons
• only electrons

How are the elements in the modern periodic table arranged?

• In alphabetical order
• by atomic mass
• by date of discovery
• by number of protons

Which elements are LEAST LIKELY to combine with other elements?

• halogens
• noble gases
• alkaline metals
• transition metals

Carbon and oxygen combine chemically to form carbon dioxide.  Carbon dioxide is

• an ion
• a nucleus
• a compound
• an atom

Crystals can be made up of which of the following kinds of properties?

• atoms only
• atoms or ions
• atoms, ions, or molecules
• molecules only

Which of these is NOT made up of two or more substances that are combined physically?

• homogeneous mixture
• compound
• heterogeneous mixture
• solution

Filtration can be used to separate a mixture of ... 

• a solid and a liquid
• a liquid and a gas
• two liquids
• two solids

What happens during a physical change?

• new substances form
• the identity of a substance is changed
• A chemical reaction occurs
• a property of the substance changes but its identity stays the same

which of the following is a chemical change?

• water boiling
• paper being cut
• ice melting
• iron rusting