4. Atoms and Elements

Which of the following is an isotope of lithium?

An atom has 53 protons and 74 neutrons. Which isotope is it?

Which statement best describes an isotope such as carbon-14?

Which of the following represents an isotope of lithium (Li)?

Which element is represented by an atom with 13 protons and 14 neutrons (i.e., atomic number $13$)?

An atom has 4 protons and 5 neutrons. Which element is it?

In atomic structure, how is the mass number of an atom calculated?

An atom has 38 protons and 50 neutrons. What element is it (and what isotope is specified by these numbers)?

Which isotope has 14 protons and 15 neutrons?

How many neutrons are in an atom of magnesium-25 ($Mg-25$)? (Atomic number of Mg is 12.)

Which element is represented by an atom with 3 protons and 4 neutrons?

How do isotopes of a given element differ from one another?

Tin has atomic number 50. How many neutrons are in an atom of tin-120 (Sn-120)?

An atom has 14 protons and 15 neutrons. Which element is it (and what is the isotope’s mass number)?

Which pair of nuclide notations represent isotopes of the same element?