Which is located outside the nucleus of an atom?

• proton
• electron
• neutron
• ion

Which is a substance?

• fruit salad
• table salt
• spaghetti
• granola cereal

Which is the best model for a homogeneous mixture?

• 
• 
• 
• 

Which is a property of all atoms?

• a nucleus with a positive charge
• more electrons than protons
• same number of protons as neutrons
• a positively charged electron cloud

Which is another name for a solution?

• heterogeneous mixture
• homogeneous mixture
• compound
• A. element

Which would you most likely be able to separate into its parts by filtering?

• heterogeneous mixture of two solids
• homogeneous mixture of two solids
• heterogeneous mixture of two liquids
• homogeneous mixture of two liquids

Where is almost all the mass of an atom located?

• in the nucleus
• in the electrons
• in the protons
• in the neutrons

Which best describes an electron cloud?

• an area of charged particles with a fixed boundary
• a solid mass of charge around the nucleus
• electrons on a fixed path around the nucleus
• mostly empty space with tiny charged particles in it

Which class of matter is the least evenly mixed?

• compounds
• homogeneous mixtures
• heterogeneous mixtures
• solutions

The figure shows models of three different atoms. What can you conclude about the three models shown in the figure?

• They all show the same isotope.

• They all show the same element.

• They all show negative ions.

• They all show positive ions.