Average Atomic Mass HW FCHS Chemistry I

The atomic mass of an element is the ___.

• average of the mass number and the atomic number for the element

• weighted average of the masses of the isotopes of the element

• total mass of the isotopes of the element

• total number of subatomic particles in the nucleus

The box for an element from the periodic table is shown. Which is the atomic mass?

• A

• B

• C

• D

In order for two elements to be isotopes, what has to be the SAME?

• Protons

• Electrons

• Neutrons

• Mass

In order for two elements to be isotopes, what must be DIFFERENT?

• Protons

• Electrons

• Neutrons

• Neutrons & Mass

If X is the symbol for an element, which of the following two symbols represent    isotopes of the same element?  
1) ⁷⁷₃₅X 

2) ⁷⁷₃₃X

  3) ⁸¹₃₇X 

4) ⁸¹₃₅ X

• 1 and 2

• 3 and 4

• 1 and 4

• 1 and 3

Lithium has two isotopes. Li-6 and Li-7. Which is more abundant?

• Li-6

• Li-7

• impossible to tell

Which of the following could have 82 neutrons?

• W-182
• Ta-181
• Cs-132
• Ba-138

24.1% of all the isotopes of a an element have a mass of 75.23 amu, 48.7% have a mass of 74.61 amu, and 27.2% have a mass of 75.20 amu.
What is the average mass of this element?

• 74.92 amu
• 24.97 amu
• 75.01 amu
• 74.51 amu

Tags

NGSS.MS-PS1-2

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?

• 41.996 amu

• 42.191 amu

• 10.432 amu

• 40.045 amu

Calculate the average atomic mass of silver.

• 106.38649amu
• 111.91896amu
• 107.8677amu
• 121