How many protons does this isotope of titanium have?

How many neutrons does the isotope of lithium have?

How many neutrons does uranium-235 have?

• 238
• 92
• 146
• 143

What do these isotopes of carbon all have in common?

• neutrons

• mass number

• atomic number

• atomic weight

In a correctly written symbol what would be located in the "A" position?

• number of neutrons
• atomic number
• number of electrons 
• mass number

What quantities vary between isotopes of an element?

• protons, electrons, and atomic mass

• protons, electrons, and atomic number

• neutrons and electrons

• neutrons and mass number

The _________ of an element equals the number of protons in an atom of that element.

• mass number
• neutrons
• atomic number
• isotopes

What is the mass number of this copper atom?

What is the atomic number of this copper atom?

How many protons are in this atom of copper?

• 29

• 63

• 34

• 91