4. Atoms and Elements

Which of the following isotopes is not possible (i.e., would correspond to an element that cannot exist because its atomic number would be 0)?

In nature, bromine occurs primarily as two stable isotopes, 79Br and 81Br. Which isotope is slightly more abundant and therefore the most common isotope of bromine?

An atom has 31 protons and 37 neutrons. What element is it?

How many protons are in an atom of strontium-90?

An atom has 18 protons and 22 neutrons. Which element is it, and what is its mass number?

Titanium-48 is an isotope of titanium. How many protons does a neutral atom of $T^{48}i$ have?

Which element is represented by an atom that has 14 protons and 14 neutrons?

An atom with 3 protons and 4 neutrons is which isotope?

Which of the following atoms has the smallest number of neutrons?

Which neutral isotope has 17 electrons and 18 neutrons?

A typical neon atom is the most abundant isotope, neon-20. How many neutrons does a ${20}^{\mathrm{Ne}}$ atom have?

Which isotope has 17 protons and 18 neutrons?

Supply the missing information in the following table: