Atomic Structure & Isotopes

What is the approximate mass of an atom that contains 26 protons, 26 electrons and 19 neutrons?

• 26 amu

• 45 amu

• 52 amu

• 71 amu

Two atoms that are different isotopes of the same element have

• the same number of protons and same number of neutrons

• the same number of protons but a different number of neutrons

• a different number of protons but the same number of neutrons

• a different number of protons and a different number of neutrons

Which notations represent atoms that have the same number of protons but a different number of neutrons?

• H-2 and He-3

• S-32 and S-32

• Cl-35 and Cl-37

• Ga-70 and Ge-73

Atoms are neutral because the number of

• protons equals the number of neutrons

• protons equals the numbers of electrons

• neutrons is greater than the number of protons

• neutrons is greater than the number of electrons

Which notations represent hydrogen isotopes?

• 
• 
• 
• 

Which atom has the same number of neutrons as the isotope above? 

• 
• 
• 
• 

Which statement describes the structure of an atom?

• The nucleus contains positively charged electrons

• the nucleus contains negatively charged protons

• the nucleus has a positive charge and is surrounded by negatively charged electrons

• the nucleus has a negative charge and is surrounded by positively charged electrons

On the periodic table, the number of protons in an atom of an element is indicated by its

• atomic mass

• atomic number

• selected oxidation states

• number of valence electrons

A neutral atom contains 12 neutrons and 11 electrons. The number of protons in this atom is

• 1

• 12

• 11

• 23

All phosphorus atoms have the same

• mass number

• number of neutrons plus number of electrons

• number of neutrons

• number of protons