Question

1- An atom has a mass number of 24 and 13 neutrons. What is the atomic number of this atom?

2-Give the nuclear symbol for the isotope of argon for which A=38?
Enter the nuclear symbol for the isotope (e.g., 42He).

Answer 1

The atomic number of an atom with a mass number of 24 and 13 neutrons is 11, corresponding to sodium (Na). The nuclear symbol for the isotope of argon with a mass number of 38 is ^{38}_{18}Ar.

Step-by-step explanation:

To answer the first question, we need to determine the atomic number of an atom that has a mass number of 24 and 13 neutrons. The atomic number is equal to the number of protons in an atom, and given that the mass number is the sum of protons and neutrons, we can calculate the number of protons by subtracting the number of neutrons from the mass number:
Atomic number = Mass number - Number of neutrons
Atomic number = 24 - 13
Atomic number = 11

Therefore, the atomic number of this atom is 11, which corresponds to the element sodium (Na).

For the second question, the nuclear symbol for the isotope of argon with a mass number (A) of 38 is 38Ar. The atomic number of argon is 18, and it is typically written as a subscript before the symbol: 3818Ar.

Answer 2

1.- The mass number of an atom equals the number of neutrons plus the number of protons. Then, for this atom the number of protons equals 24 less 13 = 11. The number of protons is the atomic number, so the answer is that the atomic number is 11.

2.- A = 38, means that the isotope of argon has mass number of 38. Given that the atomic number of argon is 18, this isotope has 18 protons and 38 less 18 = 20 neutrons.Then, the nuclear symbol is Ar precedeed by the numbers 38 (upper left corner) and 18 (lower left corner).