#: Class: Date: Isotopes and Average Atomic Mass 



Yüklə 9,56 Kb.
tarix05.03.2018
ölçüsü9,56 Kb.

Name: KEY #: _____ Class: _____ Date: _________________

Isotopes and Average Atomic Mass 



Use the information given about each element to determine if the pair of elements are isotopes or different elements.

  1. Element D has 6 protons and 7 neutrons.

Element F has 7 protons and 7 neutrons. Different elements



  1. Element J has 27 protons and 32 neutrons.

Element L has 27 protons and 33 neutrons. Isotopes


  1. Element X has 17 protons and 18 neutrons.

Element Y has 18 protons and 17 neutrons. Different elements

  1. Element Q has 56 protons and 81 neutrons.

Element F has 56 protons and 82 neutrons. Isotopes


  1. Element T has an atomic number 20 and mass number 40.

Element Z has an atomic number 20 and mass number 41. Isotopes


  1. Element P has an atomic number 92 and mass number 238. Isotopes

Element S has 92 protons and 143 neutrons.
The average atomic mass is the weighted average of all the isotopes of an element. Determine the average atomic mass.


  1. Rubidium is a soft, silvery-white metal that has two common isotopes, 85Rb and 87Rb. If the abundance of 85Rb is 72.2% and the abundance of 87Rb is 27.8%, what is the average atomic mass of rubidium?

85Rb 0.722 x 85= 61.37
87Rb 0.278 x 87= + 24.186
86.556 amu

  1. Naturally occurring chlorine that is put in pools is 75.53% 35Cl and 24.47% 37Cl. Calculate the average atomic mass.

35Cl 0.7553 x 35= 25.4355
37Cl 0.2447 x 37= +9.0539
34.4894 amu

  1. Copper used in electric wires comes in two isotopes: 63Cu and 65Cu. 63Cu has an abundance of 69.09%. The other isotope, 65Cu, has an abundance of 30.91%. Calculate the average atomic mass of copper.
    63Cu 0.6909 x 63= 43.5267
    65Cu 0.3091 x 65= +20.0915
    63.6182 amu

  2. Hydrogen has three common isotopes: 1H (99%), 2H (0.8%), and 3H (0.2%). What is the average atomic mass of hydrogen?

1H 0.99 x 1= 0.99
2H 0.008 x 2 0.016
3H 0.002 x 3= + 0.006
1.012 amu



Dostları ilə paylaş:


Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©genderi.org 2019
rəhbərliyinə müraciət

    Ana səhifə