WEEK 13 - QUIZ : ISOTOPE AND CALCULATING AVERAGE ATOMIC MASS

An element has two naturally occurring isotopes. One is 10.013 amu and is 19.9% abundant. The other is 11.01 amu and is 80.1% abundant. What is the average atomic mass? What element is it?

• 9.012, Beryllium
• 12.011, Carbon
• 6.941, Lithium
• 10.8, Boron

An isotope has three forms.  20% have a mass of 3 amu, 10% have a mass of 5 amu and 70% have a mass of 4 amu.  The average atomic mass will be closest to

• 2 amu
• 3 amu
• 4 amu
• 5 amu

Compute the average atomic mass for silicon:

• 27.977
• 28.09
• 28.976
• The average mass cannot be determined from provided information.

4.35% of all X atoms have a mass of 39.946 amu. 83.79% have a mass of 41.941 amu, 9.50% have a mass of 42.941 amu, and 2.36% have a mass of 43.939 amu. What is the average atomic mass of atom X?

• 41.97 amu
• 42.19 amu
• 10.43 amu
• 40.04 amu

To calculate average atomic mass, you need

• the atomic mass of each isotope

• the percent abundance of each isotope

• the atomic mass and percent abundance of each isotope

• to find the average of the atomic masses of each isotope

How many neutrons does an atom of the isotope Neon-22 have?

• 12
• 10
• 22
• 20

If X is the symbol for an element, which of the following two symbols represent    isotopes of the same element?     I. ⁷⁷₃₅X  II. ⁷⁷₃₃X  III. ⁸¹₃₇X  IV. ⁸¹₃₅ X

• I and II
• III and IV
• I and IV
• I and III

Tags

NGSS.HS-PS1-8

How many neutrons does the isotope below have?     ⁸⁹ ₃₆Kr

• 53
• 36
• 89
• 125

What quantities vary between isotopes of an element?

• protons, electrons, and atomic mass
• protons, electrons, and atomic number
• neutrons and electrons
• neutrons and mass number

Tags

NGSS.HS-PS1-8

In a correctly written symbol what would be located in the "A" position?

• number of neutrons
• atomic number
• number of electrons 
• mass number

Tags

NGSS.HS-PS1-7