Question

What are the atomic number and mass number of the elements represented by the symbols 817P, 1840Q, 168P, 2040R?

a) 817P: Atomic Number = 81, Mass Number =7
b) 1840Q: Atomic Number = 18, Mass Number = 40
c) 168P: Atomic Number = 16, Mass Number = 8
d) 2040R: Atomic Number =20 , Mass Number = 40

Answer 1

The correct atomic number and mass number for each element are as follows: 1840Q has an atomic number of 18 and a mass number of 40, and 2040R has an atomic number of 20 and a mass number of 40. The other two symbols likely contain typographical errors but should represent lithium and oxygen if corrected.

Step-by-step explanation:

The elements represented by the symbols 817P, 1840Q, 168P, and 2040R each have an atomic number (the number of protons in an atom) and a mass number (the total number of protons and neutrons in the atom's nucleus). The correct atomic number and mass number for each element are as follows:

• 817P: This notation is likely incorrect as the atomic number cannot be higher than the mass number. However, if the symbol was intended to be 317P, then Atomic Number = 3 (for lithium), and Mass Number = 17.
• 1840Q: Atomic Number = 18 (argon), and Mass Number = 40.
• 168P: This notation is again likely incorrect as the atomic number cannot be higher than the mass number. If the correct symbol was intended to be 168O, then Atomic Number = 8 (oxygen), and Mass Number = 16.
• 2040R: Atomic Number = 20 (calcium), and Mass Number = 40.