Unit 3: The Periodic Table + Isotopes

The nucleus of an atom contains which subatomic particles?

• protons and electrons

• protons and neutrons

• electrons and neutrons

• protons, electrons, and neutrons

In a neutrally charged atom, which two subatomic particles are equal in number?

• protons and neutrons

• all subatomic particles are equal in number

• neutrons and electrons

• protons and electrons

Which subatomic particle is counted to determine the type of element the atom represents?

• proton

• neutron

• electron

• boron

Particles in an atom that have no charge are 

• negatrons 

• electrons 

• neutrons 

• protons 

How many neutrons are in an atom of "K"?

• 29

• 19

• 58

• 20

The atomic number is equal to _.

• the number of protons and also electrons

• the number of neutrons only

• the total number of protons and neutrons

• the number of protons, neutrons, and electrons

Adding or subtracting neutrons from an atom means it is now a(n)...

• ion

• mixture

• isotope

• neutral atom

The atomic mass is equal to _.

• the number of protons only
• the number of neutrons only
• the total number of protons and neutrons
• the number of protons, neutrons, and electrons.

Can the mass number of an atom change?

• yes, if its number of protons changes

• yes, if its number of neutrons changes

• yes, if its number of electrons changes

• no, it always stays the same

Select all that is true: We cannot change an atom's number of protons because...

• protons = atomic number and we can't change an element into another element

• changing the number of protons an atom has would mean it has changed into another element

• because protons have no mass

• we can change the number of neutrons, not protons