1. Fill in the blanks in the following chart Element Element Symbol Potassium K 19 19 Atomic # # protons # Mass # neutrons Nuclear symbol Isotope name 39 20 39 19 K Aluminum AI 13 13 14 27 84 209 Iron-56

For each of the isotopes in Exercise 21.1, determine the numbers of protons, neutrons, and electrons in a neutral atom of the isotope.

What is the nuclide symbol for the nucleus that contains 11 protons and 12 neutrons?

1. The mass of an atom of manganese is 54.9380 u. How many neutrons are contained in one atom of this element? 25 29 30 55

Give the atomic number (Z) and the mass number (A) for each of the following: a. a carbon atom with 8 neutrons b. an aluminum atom with 14 neutrons c. an argon atom with 20 neutrons d. a copper atom with 36 neutrons

The following isotopes are important in nuclear power. Write their symbols in the form XZA. a. U-235 b. U-238 c. Pu-239 d. Xe-144

Define the term atomic weight. Why might the values of atomic weights on a planet elsewhere in the universe be different from those on earth?

Though the common isotope of aluminum has a mass number of 27, isotopes of aluminum have been isolated (or prepared in nuclear reactors) with mass numbers of 24, 25, 26, 28, 29, and 30. How many neutrons are present in each of these isotopes? Why are they all considered aluminum atoms, even though they differ greatly in mass? Write the atomic symbol for each isotope.

An element has the following natural abundances and isotopic masses: 90.92% abundance with 19.99 amu, 0.26% abundance with 20.99 amu, and 8.82% abundance with 21.99 amu. Calculate the average atomic mass of this element.

For the following isotopes that have missing information, fill in the missing information to complete the notation (a) X1434 (b) PX36 (c) MX57n (d) X56121